docs(aio): rename cb- files and a few others

aio/content/examples/form-validation/src/app/app.module.ts

@@ -0,0 +1,18 @@
+// #docregion
+import { NgModule }      from '@angular/core';
+import { BrowserModule } from '@angular/platform-browser';
+
+import { AppComponent }           from './app.component';
+import { HeroFormTemplateModule } from './template/hero-form-template.module';
+import { HeroFormReactiveModule } from './reactive/hero-form-reactive.module';
+
+@NgModule({
+  imports: [
+    BrowserModule,
+    HeroFormTemplateModule,
+    HeroFormReactiveModule
+  ],
+  declarations: [ AppComponent ],
+  bootstrap:    [ AppComponent ]
+})
+export class AppModule { }