message: docs(operators):correct example
diff: @@ -26,10 +26,10 @@ import { Operator } from '../Operator';
  * In every window of 1 second each, emit at most 2 click events
  * ```javascript
  * const clicks = fromEvent(document, 'click');
  - * const interval = interval(1000);
  + * const sec = interval(1000);
  * const result = clicks.pipe(
  - * window(interval),
  - * map(win => win.take(2)), // each window has at most 2 emissions
  + * window(sec),
  + * map(win => win.pipe(take(2))), // each window has at most 2 emissions
  * mergeAll(), // flatten the Observable-of-Observables
  * );
  * result.subscribe(x => console.log(x));
  