doc/neovim: update treesitter section

[mrcjkb]

The tree-sitter documentation in neovim.section.md is a bit dated (after the switch to from master to main, see #470883).

This PR aims to improve the documentation by:

• Clarifying the two setup approaches (with nvim-treesitter vs. standalone grammars)
• Providing guidance on enabling tree-sitter features like syntax highlighting and folding
• Adding maintainer documentation for handling plugins with tree-sitter grammar dependencies

Things done

• Built on platform:
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS tests in nixos/tests.
  • Package tests at passthru.tests.
  • Tests in lib/tests or pkgs/test for functions and "core" functionality.
• Ran nixpkgs-review on this PR. See nixpkgs-review usage.
• Tested basic functionality of all binary files, usually in ./result/bin/.
• Nixpkgs Release Notes
  • Package update: when the change is major or breaking.
• NixOS Release Notes
  • Module addition: when adding a new NixOS module.
  • Module update: when the change is significant.
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other READMEs.

[khaneliman]

Some good snippets of info for anyone trying to figure out how to get started, thanks!

[mrcjkb]

Update: Replaced all occurrences of "tree-sitter" with "treesitter" for consistency (upstream spells it "tree-sitter", but the Neovim community spells it "treesitter").

[PerchunPak]

It doesn't look good in the result file, I'd avoid lists here

Suggested change

	[Treesitter](https://tree-sitter.github.io/) provides syntax parsing for Neovim, enabling features like:
	- Advanced syntax highlighting
	- Code folding
	- Indentation
	- ...and more
	[Treesitter](https://tree-sitter.github.io/) provides syntax parsing for Neovim, enabling features like: Advanced syntax highlighting, Code folding, Indentation and more

[khaneliman]

Should be able to just indent the lists too

[mrcjkb]

I've inlined the tree-sitter features list, but I don't think the other lists need to be indented as it would be inconsistent with existing lists on this page.

Various things look a bit off in the result file (for example, the ::: {.important} block has a white background with white text). I wouldn't see those as a blocker for this PR - that's a different issue (if it affects the nixpkgs manual that gets published).

[teto]

this is awesome

[teto]

I have a last request before merging. I built this locally and noticed the treesitter bits dont appear in the neovim TOC (table of content). It's true on master https://nixos.org/manual/nixpkgs/unstable/#neovim .
It makes the subcategories more hidden than they should so I suggest that you use h2 title level (or whatever it's called), ie
#### Treesitter {#neovim-plugin-treesitter} should become ## Treesitter, likewise for the other sections.

[mrcjkb]

I have a last request before merging. I built this locally and noticed the treesitter bits dont appear in the neovim TOC (table of content). It's true on master https://nixos.org/manual/nixpkgs/unstable/#neovim . It makes the subcategories more hidden than they should so I suggest that you use h2 title level (or whatever it's called), ie #### Treesitter {#neovim-plugin-treesitter} should become ## Treesitter, likewise for the other sections.

Sure. I've added a second commit.