refactor(lua): improve type annotations

scripts/luacats_parser.lua

@@ -46,6 +46,7 @@ local luacats_grammar = require('scripts.luacats_grammar')
 --- @field type string
 --- @field desc string
 --- @field access? 'private'|'package'|'protected'
+--- @field nodoc? true
 
 --- @class nvim.luacats.parser.class
 --- @field kind 'class'
@@ -270,6 +271,7 @@ local function fun2field(fun)
     type = table.concat(parts, ''),
     access = fun.access,
     desc = fun.desc,
+    nodoc = fun.nodoc,
   }
 end