message: docs(Observable): change the example with error handling
  remove unnecessary try/catch
  fix
diff: @@ -360,20 +360,23 @@ const observable = new Observable(function subscribe(subscriber) {
  });
  ```
  -It is a good idea to wrap any code in `subscribe` with `try`/`catch` block that will deliver an Error notification if it catches an exception:
  +It is a good point to mention that `try`/`catch` is unnecessary because even without it exceptions are delivered to the error notification:
  ```ts
  import { Observable } from 'rxjs';
  const observable = new Observable(function subscribe(subscriber) {
  - try {
  subscriber.next(1);
  subscriber.next(2);
  subscriber.next(3);
  + foo(); // Calls subscriber.error!
  subscriber.complete();
  - } catch (err) {
  - subscriber.error(err); // delivers an error if it caught one
  - }
  +});
  +
  +observable.subscribe({
  + next(x) { console.log('got value ' + x); },
  + error(err) { console.error('something wrong occurred: ' + err); },
  + complete() { console.log('done'); }
  });
  ```
  