feat(docs): replace lua2dox.lua

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).

1 files changed, 1 insertions, 1 deletions

diff --git a/runtime/lua/vim/_meta/json.lua b/runtime/lua/vim/_meta/json.lua
index e010086615..07d89aafc8 100644
--- a/runtime/lua/vim/_meta/json.lua
+++ b/runtime/lua/vim/_meta/json.lua
@@ -5,7 +5,7 @@ vim.json = {}
 
 -- luacheck: no unused args
 
----@defgroup vim.json
+---@brief
 ---
 --- This module provides encoding and decoding of Lua objects to and
 --- from JSON-encoded strings. Supports |vim.NIL| and |vim.empty_dict()|.