Rename the `it`/`describe` blocks for tests for the
`getDocumentMetadata` method to make it clearer what APIs the tests
refer to.

This also includes some minor related cleanup:

 - Function expressions => arrow functions
 - Fix a test for Twitter metadata being disabled because it was embedded within another test
 - Remove a duplicated test for the `uri` method

 - Extract `Link` type used in several places and document it as the
   return type of `_getLinks`
 - Document the `metadata` argument to `getLinks` and provide a default
   value for it
 - Add a comment to clarify why `_getLinks` is called in the `uri`
   method

`getDocumentMetadata` returns the first available title from a
prioritized list of sources. Previously the tests only checked the
highest priority source. Update the test so that it covers all cases.

The `HTMLMetadata` class provided two ways to get at the document
metadata:

 1. A `getDocumentMetadata` method which reads the current metadata from
    the document and returns it
 2. A `metadata` field which returns the last-read metadata

The `metadata` field was not used outside the tests and shouldn't be used
because it might return stale metadata (in a web page with client-side
JS that updates `<meta>` and `<link>` tags etc. after the page loads). This field
was also used internally by the various helper methods that gather metadata,
with non-obvious constraints on the order in which the helpers are called.

Remove the field to prevent external mis-use of the class and make the data flow
and dependencies clearer internally.

Bumps [prettier](https://github.com/prettier/prettier) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/main/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/compare/2.3.0...2.3.1)

---
updated-dependencies:
- dependency-name: prettier
  dependency-type: direct:development
  update-type: version-update:semver-patch
...
Signed-off-by: dependabot[bot] <support@github.com>

This reverts commit 719da85b2e82bff166376f337ff4bd5f90bb5e35.

This reverts commit e4b6004183fc4fe8b8b10000c700cdb4613b528d.

Currently, this config value is unused, but added for test coverage

The main difference is that configFrom returned config key:value pairs, but now configDefinitions returns key:object pairs. Where the object may hold additional flags and methods for each specific config value. Currently the only method included is valueFn() which gets the value from its source. Others will follow.

- Refactor config index to expose a different method for getting the config called `getConfig`. This now takes a app name (context) as a string which may return a subset of config values appropriate for a given application such as the "sidebar" or "notebook".
- Segregate the config keys into various app contexts and omit keys that are either not used in a given application context or need to be excluded (e.g. `annotations` in notebook)
- Fix missing config appType in annotator/config/index so it can propagate to the sidebar property (this was previously not the case)
- Remove assetRoot from annotator/config/index as it is only needed in boot and not any specific app context

Bumps [axe-core](https://github.com/dequelabs/axe-core) from 4.2.1 to 4.2.2.
- [Release notes](https://github.com/dequelabs/axe-core/releases)
- [Changelog](https://github.com/dequelabs/axe-core/blob/v4.2.2/CHANGELOG.md)
- [Commits](https://github.com/dequelabs/axe-core/compare/v4.2.1...v4.2.2)

---
updated-dependencies:
- dependency-name: axe-core
  dependency-type: direct:development
  update-type: version-update:semver-patch
...
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Bumps [core-js](https://github.com/zloirock/core-js/tree/HEAD/packages/core-js) from 3.13.1 to 3.14.0.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zloirock/core-js/commits/v3.14.0/packages/core-js)

---
updated-dependencies:
- dependency-name: core-js
  dependency-type: direct:development
  update-type: version-update:semver-minor
...
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Bumps [puppeteer](https://github.com/puppeteer/puppeteer) from 9.1.1 to 10.0.0.
- [Release notes](https://github.com/puppeteer/puppeteer/releases)
- [Changelog](https://github.com/puppeteer/puppeteer/blob/main/CHANGELOG.md)
- [Commits](https://github.com/puppeteer/puppeteer/compare/v9.1.1...v10.0.0)

---
updated-dependencies:
- dependency-name: puppeteer
  dependency-type: direct:development
  update-type: version-update:semver-major
...
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Bumps [@octokit/rest](https://github.com/octokit/rest.js) from 18.5.5 to 18.5.6.
- [Release notes](https://github.com/octokit/rest.js/releases)
- [Commits](https://github.com/octokit/rest.js/compare/v18.5.5...v18.5.6)

---
updated-dependencies:
- dependency-name: "@octokit/rest"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...
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Bumps [karma](https://github.com/karma-runner/karma) from 6.3.2 to 6.3.3.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](https://github.com/karma-runner/karma/compare/v6.3.2...v6.3.3)

---
updated-dependencies:
- dependency-name: karma
  dependency-type: direct:development
  update-type: version-update:semver-patch
...
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Bumps [aws-sdk](https://github.com/aws/aws-sdk-js) from 2.918.0 to 2.922.0.
- [Release notes](https://github.com/aws/aws-sdk-js/releases)
- [Changelog](https://github.com/aws/aws-sdk-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-js/compare/v2.918.0...v2.922.0)

---
updated-dependencies:
- dependency-name: aws-sdk
  dependency-type: direct:development
  update-type: version-update:semver-minor
...
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Bumps [sass](https://github.com/sass/dart-sass) from 1.34.0 to 1.34.1.
- [Release notes](https://github.com/sass/dart-sass/releases)
- [Changelog](https://github.com/sass/dart-sass/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sass/dart-sass/compare/1.34.0...1.34.1)

---
updated-dependencies:
- dependency-name: sass
  dependency-type: direct:development
  update-type: version-update:semver-patch
...
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Allow the `initialState` argument to `createStoreModule` to be a value
to simplify usage for modules where the initial state is a static value
(ie. has no dependency on data in `settings`).

Improve the type of the `selectors` argument to `createStoreModule` to
link it to the type of the initial state returned by the `initialState`
argument. This enables TS to check/infer that the first argument to
these functions should be of the same type that `initialState` returns.

In the process it was necessary to remove the `ModuleConfig` type and
declare the type of `createStoreModule`'s `config` argument inline.
This works around a TypeScript limitation [1]:

```
@template State
@template {SelectorMap<State>} Selectors // Unexpected error
...
@typedef ModuleConfig
```

But this works:

``
@template State
@template {SelectorMap<State>} Selectors // OK
...
function createStoreModule(...) { ... }
```

[1] https://github.com/microsoft/TypeScript/issues/43403

Extract the `initialState` property out of the `config` object passed
to `createStoreModule` into a separate argument which is passed before
`config`. This allows TypeScript to infer the type of fields/parameters
etc. which refer to the module state while processing the `config`
argument.

For example, given the following:

```
export default createStoreModule(initialState, {
  reducers: {
    updateThing(state, action) {
      ...
    }
  }
});
```

TS can infer the type of the `state` argument to `updateThing` without
needing to explicitly annotate it. The same approach can work for other
fields as well. This inference does not work when `initialState` is a
property of the `config` object however.

This function was originally written as a helper to enable us to enable
TypeScript to generate more useful errors if a store module had the
wrong structure. However it also provides a place that we can do runtime
checks / normalization of store modules etc.

Rename the function and update the documentation to make it clear that
this is the correct way to define a store module.

Rename several fields of the configuration object for store modules to
better align with the associated Redux concepts. This should make it
easier for newcomers to the code to understand it if they already have
some familiarity with Redux.

 - Rename the `init` function to `initialState`
 - Rename the `update` map to `reducers`
 - Rename the `actions` map to `actionCreators`

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.4 to 1.26.5.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](https://github.com/urllib3/urllib3/compare/1.26.4...1.26.5)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: indirect
...
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [@sentry/browser](https://github.com/getsentry/sentry-javascript) from 6.4.1 to 6.5.0.
- [Release notes](https://github.com/getsentry/sentry-javascript/releases)
- [Changelog](https://github.com/getsentry/sentry-javascript/blob/master/CHANGELOG.md)
- [Commits](https://github.com/getsentry/sentry-javascript/compare/6.4.1...6.5.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [eslint-plugin-mocha](https://github.com/lo1tuma/eslint-plugin-mocha) from 8.1.0 to 9.0.0.
- [Release notes](https://github.com/lo1tuma/eslint-plugin-mocha/releases)
- [Changelog](https://github.com/lo1tuma/eslint-plugin-mocha/blob/master/CHANGELOG.md)
- [Commits](https://github.com/lo1tuma/eslint-plugin-mocha/compare/8.1.0...9.0.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [mustache-express](https://github.com/bryanburgers/node-mustache-express) from 1.3.0 to 1.3.1.
- [Release notes](https://github.com/bryanburgers/node-mustache-express/releases)
- [Commits](https://github.com/bryanburgers/node-mustache-express/commits)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [@octokit/rest](https://github.com/octokit/rest.js) from 18.5.3 to 18.5.5.
- [Release notes](https://github.com/octokit/rest.js/releases)
- [Commits](https://github.com/octokit/rest.js/compare/v18.5.3...v18.5.5)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 10.2.5 to 10.2.6.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/compare/10.2.5...10.2.6)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [core-js](https://github.com/zloirock/core-js/tree/HEAD/packages/core-js) from 3.12.1 to 3.13.1.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zloirock/core-js/commits/v3.13.1/packages/core-js)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [typescript](https://github.com/Microsoft/TypeScript) from 4.2.4 to 4.3.2.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](https://github.com/Microsoft/TypeScript/compare/v4.2.4...v4.3.2)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [eslint-plugin-react](https://github.com/yannickcr/eslint-plugin-react) from 7.23.2 to 7.24.0.
- [Release notes](https://github.com/yannickcr/eslint-plugin-react/releases)
- [Changelog](https://github.com/yannickcr/eslint-plugin-react/blob/master/CHANGELOG.md)
- [Commits](https://github.com/yannickcr/eslint-plugin-react/compare/v7.23.2...v7.24.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [@babel/preset-env](https://github.com/babel/babel/tree/HEAD/packages/babel-preset-env) from 7.14.2 to 7.14.4.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/main/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/commits/v7.14.4/packages/babel-preset-env)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [sinon](https://github.com/sinonjs/sinon) from 10.0.0 to 11.1.1.
- [Release notes](https://github.com/sinonjs/sinon/releases)
- [Changelog](https://github.com/sinonjs/sinon/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sinonjs/sinon/compare/v10.0.0...v11.1.1)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [aws-sdk](https://github.com/aws/aws-sdk-js) from 2.912.0 to 2.918.0.
- [Release notes](https://github.com/aws/aws-sdk-js/releases)
- [Changelog](https://github.com/aws/aws-sdk-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-js/compare/v2.912.0...v2.918.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [ws](https://github.com/websockets/ws) from 7.4.2 to 7.4.6.
- [Release notes](https://github.com/websockets/ws/releases)
- [Commits](https://github.com/websockets/ws/compare/7.4.2...7.4.6)
Signed-off-by: dependabot[bot] <support@github.com>

`externalContainerSelector` allows the placement of the sidebar inside
the element specified by the CSS selector.

See https://h.readthedocs.io/projects/client/en/latest/publishers/config/#cmdoption-arg-externalcontainerselector