add item set and menu item set CRUD

test/system/menu_item_sets_test.rb

@@ -0,0 +1,9 @@
+require "application_system_test_case"
+
+class Settings::MenuItemSetsTest < ApplicationSystemTestCase
+  # test "visiting the index" do
+  #   visit settings_menu_item_sets_url
+  #
+  #   assert_selector "h1", text: "Settings::MenuItemSet"
+  # end
+end