message: docs(fromEvent): get click events from document, rather than button
  hi.
  `Error: button is not defined`
  `Error: clicks$ is not defined`
diff: @@ -14,12 +14,12 @@ import { MonoTypeOperatorFunction } from '../types';
  * import { fromEvent, timer } from 'rxjs';
  * import { throwIfEmpty, takeUntil } from 'rxjs/operators';
  *
  - * const click$ = fromEvent(button, 'click');
  + * const click$ = fromEvent(document, 'click');
  *
  - * clicks$.pipe(
  + * click$.pipe(
  * takeUntil(timer(1000)),
  * throwIfEmpty(
  - * () => new Error('the button was not clicked within 1 second')
  + * () => new Error('the document was not clicked within 1 second')
  * ),
  * )
  * .subscribe({
  