RFC: Changes to highlights

[mvllow]

Neovim recently changed/added several treesitter highlight groups, adapted to our Neovim theme in rose-pine/neovim#217. Now is a good time to discuss changes to the Helix theme to add better semantic support. Our Neovim theme should be an inspiration but not a limitation. Any feedback or suggestions are much appreciated—with screenshots if possible.

Some previous discussion exists in #7.

Here's the current tracking list:

• Ensure tree-sitter highlights are up to date
• Distinguish popup menu (completions) active item with background, similar to the fuzzy finder list

[LeoniePhiline]

Thanks for taking our concerns seriously! 🩵

And for hoisting this discussion into a new issue. Very much appreciated!