Remove the need to define the type of store created by each module
manually by adding a `StoreFromModule` helper in `create-store.js` which
can infer the store type from a store module configuration. Using this
the type of a store composed from several modules can then be created
with:

```
import fooModule from './modules/foo';
import barModule from './modules/bar';

// Define type of store returned by `createStore([fooModule, barModule])`
/** @typedef {StoreType<fooModule> & StoreType<barModule>} AppStore */
```

Ideally `createStore` would just infer the type based upon its
arguments. I haven't worked out how to do that yet. Nevertheless, this
still removes the need for a lot of manually defined types.

To ensure more useful error messages from TS if a store module's configuration
has the wrong shape a `storeModule` helper has been added. This wraps
the configuration for each module to check its shape before the
individual modules are combined into one type for the store. This helper could
also perform runtime validation in future.

 - Add `StoreFromModule` type in `create-store.js` and several helpers
   to support it
 - Modify each store module to wrap the export in `storeModule` and
   remove any manually defined store types