Add syntax highlighting queries

[Wilfred]

This is largely based on the nvim-treesitter highlighting, but enables other tree-sitter-kotlin projects to include syntax highlighting.

[fwcd]

Wow, this is pretty cool, thanks!

I haven't looked that much into tree-sitter's built-in support for syntax highlighting yet, but I hope to find some time to do so soon and get this merged.

[MolotovCherry]

Tree sitter wasm is giving me some errors with this one RangeError: Bad node name 'character_escape_seq' and when I comment that one out I get Bad node name '' (seems something with the operator section, but can't figure out what)

Edit: "?." and "!is"

[RenFraser]

Has there been any update on this pr? I'm keen to try it! :)