message: docs(router): filter the event to subscribe
  The current code will not work as the `e` will be an event,
  If we try to access e.id and e.url it will throw an exception, the correct way is to use map or filter down to specific events
  PR Close
diff: @@ -30,8 +30,8 @@ export type NavigationTrigger = 'imperative'|'popstate'|'hashchange';
  * class MyService {
  * constructor(public router: Router, logger: Logger) {
  * router.events.pipe(
  - * filter(e => e instanceof RouterEvent)
  - * ).subscribe(e => {
  + * filter((e: Event): e is RouterEvent => e instanceof RouterEvent)
  + * ).subscribe((e: RouterEvent) => {
  * logger.log(e.id, e.url);
  * });
  * }
  