this will be a tree-sitter implementation for `nix-shell` files.

try one of the following:
- `nix build` => build the parser
- `nix develop` => manually/interactively generate the parser
  - `tree-sitter generate`

non-flake equivalents:
- `nix-build`
- `nix-shell`


99% of this repository is code-gen'd garbage.
to recreate it or update it, follow this guide:
<https://tree-sitter.github.io/tree-sitter/creating-parsers>

recording my steps here to maybe someday make this reproducible: