docs(forms): add example apps for ngModelGroup (#11525)

modules/@angular/examples/forms/ts/ngModelGroup/module.ts

@@ -0,0 +1,20 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {NgModule} from '@angular/core';
+import {FormsModule} from '@angular/forms';
+import {BrowserModule} from '@angular/platform-browser';
+import {NgModelGroupComp} from './ng_model_group_example';
+
+@NgModule({
+  imports: [BrowserModule, FormsModule],
+  declarations: [NgModelGroupComp],
+  bootstrap: [NgModelGroupComp]
+})
+export class AppModule {
+}