add data argument to container:add(...)

src/logic/scripting/scripting.hpp

@@ -58,6 +58,7 @@ namespace scripting {
 
     scriptenv get_root_environment();
     scriptenv create_pack_environment(const ContentPack& pack);
+    scriptenv create_environment(const scriptenv& parent);
     scriptenv create_doc_environment(
         const scriptenv& parent, const std::string& name
     );