- Allow PDFs to benefit from shared/easily-updated client config

- Rewrite dev server as `express` app
- Add `mustache-express` as template engine
- Restructure document directories; add PDFs
- Add `pdfjs-init.js` script for embedding PDFJS with H client
- Update linting config to ignore static scripts

This changed formatting of integer values as object keys.

Bumps [prettier](https://github.com/prettier/prettier) from 2.0.5 to 2.1.0.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/master/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/compare/2.0.5...2.1.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [@sentry/browser](https://github.com/getsentry/sentry-javascript) from 5.21.1 to 5.21.4.
- [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/5.21.1...5.21.4)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [terser](https://github.com/terser/terser) from 5.1.0 to 5.2.1.
- [Release notes](https://github.com/terser/terser/releases)
- [Changelog](https://github.com/terser/terser/blob/master/CHANGELOG.md)
- [Commits](https://github.com/terser/terser/compare/v5.1.0...v5.2.1)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [chance](https://github.com/chancejs/chancejs) from 1.1.6 to 1.1.7.
- [Release notes](https://github.com/chancejs/chancejs/releases)
- [Commits](https://github.com/chancejs/chancejs/compare/1.1.6...1.1.7)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

TS 4.0 treats optional properties of type T as `T|undefined` and
produces an error if the property is used in a situation where it may
not be set.

TS 4.0 complained in a few places that this function may return
`undefined`.

Add checks or tweak the code to make it obvious to TS that a value is
not-null.

The `id` property only exists once an annotation has been saved. Add
casts in a few places where we know that this is the case.

Remove ability to construct `RPC` class without calling `new`. This
confused TypeScript's inference of the types of various fields.

Various methods in `DocumentMeta` assume that `this.metadata.{dc,
highwire, ...}` properties exist, but this is only true once the
`getDocumentMetadata()` function has been called.

Adjust the constructor so that these fields always exist.

Note that while this avoids an exception if calling certain methods before
`getDocumentMetadata`, it would still be a logical error if that
happened. For the moment such a mistake is just silently ignored.

This is a vestige of the Annotator library which is no longer needed.

This fixes errors with TS >= 4.0 which treats optional properties of
type T as being `T|undefined`.

Bumps [aws-sdk](https://github.com/aws/aws-sdk-js) from 2.735.0 to 2.739.0.
- [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/v2.735.0...v2.739.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [@babel/core](https://github.com/babel/babel/tree/HEAD/packages/babel-core) from 7.11.1 to 7.11.4.
- [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/v7.11.4/packages/babel-core)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Apologies, I seem to have introduced a bug here: https://github.com/hypothesis/client/pull/2461

It should be:

```
border-width: 0 0 1px 0;
```

rather than:

```
border: 0 0 1px 0;
```

Without this a border is set in all directions.

Since [1] PDF.js does not dispatch events to the DOM any more. Therefore
the client needs to listen for the `documentloaded` event from
`PDFApplicationViewer.eventBus`. The `eventBus` property is only
available once the viewer is initialized, so the client needs to wait
for `initializedPromise` to resolve before checking it.

[1] https://github.com/mozilla/pdf.js/pull/11655

 - Remove the IRC links since no Hypothesis staff engage with IRC any
   more as far as I am aware. We do monitor Slack however.

 - Update the Google Groups URL for the dev mailing list to point to the
   new version of Google Groups which (finally!) no longer relies on
   fragment URLs

The newest react-hooks ESLint plugin correctly reported an issue where
a `useLayoutEffect` hook had a dependency on a value which changed on
every render.

Bumps [eslint-plugin-react-hooks](https://github.com/facebook/react/tree/HEAD/packages/eslint-plugin-react-hooks) from 4.0.8 to 4.1.0.
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/master/packages/eslint-plugin-react-hooks/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/HEAD/packages/eslint-plugin-react-hooks)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

The backend Hypothesis projects have switched to using GitHub Actions
for CI. This does the same for the Hypothesis client.

Bumps [fetch-mock](https://github.com/wheresrhys/fetch-mock) from 9.10.6 to 9.10.7.
- [Release notes](https://github.com/wheresrhys/fetch-mock/releases)
- [Commits](https://github.com/wheresrhys/fetch-mock/compare/v9.10.6...v9.10.7)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [sinon](https://github.com/sinonjs/sinon) from 9.0.2 to 9.0.3.
- [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/v9.0.2...v9.0.3)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [terser](https://github.com/terser/terser) from 5.0.0 to 5.1.0.
- [Release notes](https://github.com/terser/terser/releases)
- [Changelog](https://github.com/terser/terser/blob/master/CHANGELOG.md)
- [Commits](https://github.com/terser/terser/compare/v5.0.0...v5.1.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [@sentry/browser](https://github.com/getsentry/sentry-javascript) from 5.20.1 to 5.21.1.
- [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/5.20.1...5.21.1)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

This property was not implemented when the annotation body components
were converted from Angular to Preact.

 - Add `textStyle` prop to `MarkdownView` and `MarkdownEditor` which
   sets additional CSS properties to apply to the rendered annotation
   body
 - Read the theme style properties for annotation bodies in
   `AnnotationBody` and pass the resulting `textStyle` down to
   `MarkdownEditor` and `MarkdownView`

Fixes #2444

Bumps [eslint](https://github.com/eslint/eslint) from 7.6.0 to 7.7.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/compare/v7.6.0...v7.7.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>