- Add section `VIM.LPEG` and `VIM.RE` to docs/lua.txt.
- Add `_meta/re.lua` which adds luadoc and type annotations, for the
vendored `vim.re` package.
- Fix minor style issues on `_meta/lpeg.lua` luadoc for better vimdocs
generation.
- Fix a bug on `gen_vimdoc` where non-helptags in verbatim code blocks
were parsed as helptags, affecting code examples on `vim.lpeg.Cf`,
etc.
- Also move the `vim.regex` section below so that it can be located
closer to `vim.lpeg` and `vim.re`.