Switch scollTo package to typescript

[RichardGale]

📑 Description

Renamed to typescript, added types, fixed lint errors.

viewThread uses scrollToBottom, on Reply, this jumps to position then tweens to the incorrect position. If you switch to using scrolltobottom (seemingly the public API) then Reply jumps to the correct position and stays there.

✅ Checks

• [x] My pull request adheres to the code style of this project
• [ ] My code requires changes to the documentation
• [ ] I have updated the documentation as required
• [x] All the tests have passed (TDB)

ℹ Additional Information