Method createChildMenu

include/helpers.hpp:341–345

		std::function<void(ui::Menu* menu)> createMenu;

		ui::Menu* createChildMenu() override {
			ui::Menu* menu = new ui::Menu;
			createMenu(menu);
			return menu;
		}
	};

	Item* item = createMenuItem<Item>(text, rightText + (rightText.empty() ? "" : "  ") + RIGHT_ARROW);