Added a Scroll to top keyboard shortcut for splits

[brian6932]

Pull request checklist:

• CHANGELOG.md was updated, if applicable

Description

Added a scroll to top keyboard shortcut, web chat has it, so why shouldn't Chatterino?

Web chat demo
Chatterino demo

[brian6932]

Yea I did it this way cause it was all sorted alphabetically 🤷

[zneix]

Another thing is that as we were arguing in chat and you said "you can nav any site with home and end zneix" then I'm sad to break it to you that either with or without this PR you can't scroll to neither top nor bottom of a page of e.g. emote popup or search result popup.
Just pointing that out and saying maybe this PR adds the scrolling mechanism to the wrong scope - maybe it shouldn't belong to this category/scope which it is in currently... but that'd potentially mean Ctrl+End would need to be moved as well.

[brian6932]

Yea I mean that wasn't really my intention, this is for splits. I'll refine the title and changelog entry to reflect this 👍

this nitpicking wouldn't achieve anything + my feedback is invalid.