Updated content script to use the beforeinput event

[tdulcet]

• Updated the content script to use the beforeinput event instead of the keydown and keyup events for autocorrection (see Unable to write tweets on Twitter #4 (comment)).
  • Originally designed as a fix for Unable to write tweets on Twitter #4. While it does not fix that, it may fix other site issues.
  • Improves the performance.
    • Does the autocorrections before the browser modifies the DOM tree (see here).
  • Greatly improves Android capability.
    • Eliminates dependence on the keyboard events which are poorly supported on Android (see Firefox Bug 1104817 and Chrome Bug 118639).
  • Requires Firefox/Thunderbird 87.

@rugk – I think this could be merged sometime after 2021-11-2 when Firefox/Thunderbird 78 will no longer be supported (see #4 (comment)). I would also need to make a companion PR for the Awesome Emoji Picker.

[rugk]

Some minor code-style comments, because that code is really hard to understand. It's likely because it is just a complex piece of code, but we can do better to use understandable variable names etc. 🙂

But basically LGTM.

[tdulcet]

Some minor code-style comments, because that code is really hard to understand. It's likely because it is just a complex piece of code, but we can do better to use understandable variable names etc. 🙂

Thanks. I made your requested changes in 9d9b403. I know am bad at naming stuff, so please feel free anytime to suggest better names for things. 😉