Initial revision of lua 'doc' function

luprex/core/cpp/gui.cpp

@@ -52,7 +52,7 @@ std::string Gui::menu_debug_string() const {
     return oss.str();
 }
 
-LuaDefine(gui_menu_item, "c") {
+LuaDefine(gui_menu_item, "action,label", "add a menu item to the current gui") {
     Gui *gui = Gui::fetch_global_pointer(L);
     LuaArg laction, llabel;
     LuaStack LS(L, laction, llabel);