message: docs(core): fix broken NgZone code example
  The current code example was broken as there were a couple of syntax errors. This commit fixes the demo.
  PR Close
diff: @@ -31,7 +31,7 @@ import {EventEmitter} from '../event_emitter';
  * import {NgIf} from '@angular/common';
  *
  * @Component({
  - * selector: 'ng-zone-demo'.
  + * selector: 'ng-zone-demo',
  * template: `
  * <h2>Demo: NgZone</h2>
  *
  @@ -64,8 +64,9 @@ import {EventEmitter} from '../event_emitter';
  * this._ngZone.runOutsideAngular(() => {
  * this._increaseProgress(() => {
  * // reenter the Angular zone and display done
  - * this._ngZone.run(() => {console.log('Outside Done!') });
  - * }}));
  + * this._ngZone.run(() => { console.log('Outside Done!'); });
  + * });
  + * });
  * }
  *
  * _increaseProgress(doneCallback: () => void) {
  @@ -73,7 +74,7 @@ import {EventEmitter} from '../event_emitter';
  * console.log(`Current progress: ${this.progress}%`);
  *
  * if (this.progress < 100) {
  - * window.setTimeout(() => this._increaseProgress(doneCallback)), 10)
  + * window.setTimeout(() => this._increaseProgress(doneCallback), 10);
  * } else {
  * doneCallback();
  * }
  