docs(auth): add imports for AuthProviders and AuthMethods (#628)

use AppComponent and AppModule for consistency with other docs

Author: Splaktar

docs/5-user-authentication.md

@@ -11,6 +11,10 @@ To specify your authentication ahead of time, you provide the `AngularFireModule
 with an `AuthProvider` and an `AuthMethod`.
 
 ```ts
+import { BrowserModule } from '@angular/platform-browser';
+import { NgModule } from '@angular/core';
+import { AppComponent } from './app.component';
+import { AngularFireModule, AuthProviders, AuthMethods } from 'angularfire2';
 
 const myFirebaseConfig = {
   apiKey: '<your-key>',
@@ -29,10 +33,10 @@ const myFirebaseAuthConfig = {
     BrowserModule,
     AngularFireModule.initializeApp(myFirebaseConfig, myFirebaseAuthConfig)
   ],
-  declarations: [ MyComponent ],
-  boostrap: [ MyComponent ]
+  declarations: [ AppComponent ],
+  bootstrap: [ AppComponent ]
 })
-export class MyAppModule {}
+export class AppModule {}
 ```