ref PLG-251
- Fixed comments placeholder to change from "Start the conversation" to
"Join the discussion" when there's more than 1 comment.
- Previously, it only worked after a refresh. This fix ensures it's
reactive and would update the placeholder without the need for a
refresh.
REF PLG-225
- When editing a comment, the form was not aligned correctly.
- The form has more height by default now even when not focused, to
increase engagement.
refs https://github.com/TryGhost/Product/issues/3504
- App component now uses React hooks intead of React class component
- App is now written in TypeScript
- All JavaScript is now removed from the Comments-UI project
- Removed `PopupNotification` because these were never displayed
- Removed `action` from AppContext (never used)
- Moved options parsing out of `index.ts` into a separate utility file,
similar to the signup-form
- Improved reliability of some editor tests by always waiting for the
editor to be focused (was not always the case) + added an utility method
for this
