Problem:

The documentation flow (`gen_vimdoc.py`) has several issues:
- it's not very versatile
- depends on doxygen
- doesn't work well with Lua code as it requires an awkward filter script to convert it into pseudo-C.
- The intermediate XML files and filters makes it too much like a rube goldberg machine.

Solution:

Re-implement the flow using Lua, LPEG and treesitter.

- `gen_vimdoc.py` is now replaced with `gen_vimdoc.lua` and replicates a portion of the logic.
- `lua2dox.lua` is gone!
- No more XML files.
- Doxygen is now longer used and instead we now use:
  - LPEG for comment parsing (see `scripts/luacats_grammar.lua` and `scripts/cdoc_grammar.lua`).
  - LPEG for C parsing (see `scripts/cdoc_parser.lua`)
  - Lua patterns for Lua parsing (see `scripts/luacats_parser.lua`).
  - Treesitter for Markdown parsing (see `scripts/text_utils.lua`).
- The generated `runtime/doc/*.mpack` files have been removed.
   - `scripts/gen_eval_files.lua` now instead uses `scripts/cdoc_parser.lua` directly.
- Text wrapping is implemented in `scripts/text_utils.lua` and appears to produce more consistent results (the main contributer to the diff of this change).

- remove "ran-" prefix from touch files as it's redundant since the
  they're already in the directory named `touches`.
- Include `contrib` when formatting with `make formatlua`.
- Use TARGET_FILE generator expression instead of assuming the
  executable location.
- reuse logic that determines whether to use lua or luajit.
- add translations to the `nvim` target.

Makefile improvements:
- rename variable `CMAKE_PRG` to `CMAKE` to make it more consistent with
  the builtin `MAKE` variable.
- stop propagating flags to generator. Users should use cmake for
  non-standard use cases.
- remove `+` prefix from targets. If the user for whatever reason wants
  to dry-run a target then they should be able to.

* fix(flake): clang-tools moved to nativeBuildInputs

Buildtime binaries should go in `nativeBuildInputs`
Before `clang-tools` version was overwriten breaking the Lsp.

Relevant issues:
https://github.com/NixOS/nixpkgs/issues/76486

* remove cmake, available in the nixpkgs derivation

updates nixpkgs version to reflect the removal of nvim-client in the build see https://github.com/NixOS/nixpkgs/pull/274865

Instead of a markdown file, just use a lua file instead that users can
use directly.

Flake lock file updates:
• Updated input 'flake-utils':
    'github:numtide/flake-utils/a1720a10a6cfe8234c0e93907ffe81be440f4cef' (2023-05-31)
  → 'github:numtide/flake-utils/ff7b65b44d01cf9ba6a71320833626af21126384' (2023-09-12)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/a64b73e07d4aa65cfcbda29ecf78eaf9e72e44bd' (2023-06-08)
  → 'github:nixos/nixpkgs/e92039b55bcd58469325ded85d4f58dd5a4eaf58' (2023-11-29)

Luarocks is no longer needed after
25e51d393a420765d5efd44c1b4be823a5cf280a.