feat(demo): add landing page with docs (#1951)

docs/app/@theme/services/index.ts

@@ -0,0 +1,36 @@
+/**
+ * @license
+ * Copyright Akveo. All Rights Reserved.
+ * Licensed under the MIT License. See License.txt in the project root for license information.
+ */
+
+import { NgxVersionService } from './version.service';
+import { DialogStateService } from './dialog-state.service';
+import { NgxAnalytics } from './analytics.service';
+import { NgxHighlightService } from './highlight.service';
+import { NgxMenuService } from './menu.service';
+import { NgxPaginationService } from './pagination.service';
+import { NgxStructureService } from './structure.service';
+import { NgxTabbedService } from './tabbed.service';
+import { NgxTextService } from './text.service';
+import { NgxTocStateService } from './toc-state.service';
+import { NgxCodeLoaderService } from './code-loader.service';
+import { NgxStylesService } from './styles.service';
+import { NgxIframeCommunicatorService } from './iframe-communicator.service';
+
+
+export const ngxLandingServices = [
+  NgxVersionService,
+  DialogStateService,
+  NgxAnalytics,
+  NgxHighlightService,
+  NgxMenuService,
+  NgxPaginationService,
+  NgxStructureService,
+  NgxTabbedService,
+  NgxTextService,
+  NgxTocStateService,
+  NgxCodeLoaderService,
+  NgxStylesService,
+  NgxIframeCommunicatorService,
+];