add item set and menu item set CRUD

spec/requests/settings/settings_menu_item_sets_spec.rb

@@ -0,0 +1,10 @@
+require 'rails_helper'
+
+RSpec.describe "Settings::MenuItemSets", type: :request do
+  describe "GET /settings_menu_item_sets" do
+    it "works! (now write some real specs)" do
+      get settings_menu_item_sets_path
+      expect(response).to have_http_status(200)
+    end
+  end
+end