fix(build): vimdoc tags are not validated #32801

Problem:
"make lintdoc" is not validating vimdoc (:help) tags.

Solution:
- Call `lang_tree:parse()` to init the parser.
- Load netrw 🤢 explicitly, since it was moved to `pack/dist/opt/`.
- Fix invalid help tags.

src/nvim/options.lua

@@ -6236,7 +6236,7 @@ local options = {
         	set path=,,
         <	- A directory name may end in a ':' or '/'.
         - Environment variables are expanded |:set_env|.
-        - When using |netrw.vim| URLs can be used.  For example, adding
+        - When using |netrw| URLs can be used.  For example, adding
           "https://www.vim.org" will make ":find index.html" work.
         - Search upwards and downwards in a directory tree using "*", "**" and
           ";".  See |file-searching| for info and syntax.