docs(auth): Flushed out the auth example a bit more

Author: jamesdaniels

docs/auth/getting-started.md

@@ -17,23 +17,22 @@ import * as firebase from 'firebase/app';
 @Component({
   selector: 'app-root',
   template: `
-  <div> {{ (user | async)?.uid }} </div>
-  <button (click)="login()">Login</button>
-  <button (click)="logout()">Logout</button>
+    <div *ngIf="afAuth.authState | async; let user; else showLogin">
+      <h1>Hello {{ user.displayName }}!</h1>
+      <button (click)="logout()">Logout</button>
+    </div>
+    <ng-template #showLogin>
+      <p>Please login.</p>
+      <button (click)="login()">Login with Google</button>
+    </ng-template>
   `,
 })
 export class AppComponent {
-
-  user: Observable<firebase.User>;
-
   constructor(public afAuth: AngularFireAuth) {
-    this.user = afAuth.authState;
   }
-
   login() {
     this.afAuth.auth.signInWithPopup(new firebase.auth.GoogleAuthProvider());
   }
-
   logout() {
     this.afAuth.auth.signOut();
   }