message: docs(isEmpty): improve documentation
diff: @@ -4,10 +4,10 @@ import { Observable } from '../Observable';
  import { OperatorFunction } from '../types';
  /**
  - * Emits false if the input observable emits any values, or emits true if the
  - * input observable completes without emitting any values.
  + * Emits `false` if the input Observable emits any values, or emits `true` if the
  + * input Observable completes without emitting any values.
  *
  - * <span class="informal">Tells whether any values are emitted by an observable</span>
  + * <span class="informal">Tells whether any values are emitted by an Observable.</span>
  *
  * ![](isEmpty.png)
  *
  @@ -23,42 +23,47 @@ import { OperatorFunction } from '../types';
  *
  * ## Examples
  *
  - * Emit `false` for a non-empty Observable
  - * ```javascript
  + * Emit `false` for a non-empty Observable.
  + *
  + * ```ts
  * import { Subject } from 'rxjs';
  * import { isEmpty } from 'rxjs/operators';
  *
  * const source = new Subject<string>();
  * const result = source.pipe(isEmpty());
  + *
  * source.subscribe(x => console.log(x));
  * result.subscribe(x => console.log(x));
  + *
  * source.next('a');
  * source.next('b');
  * source.next('c');
  * source.complete();
  *
  - * // Results in:
  + * // Outputs
  * // a
  * // false
  * // b
  * // c
  * ```
  *
  - * Emit `true` for an empty Observable
  - * ```javascript
  + * Emit `true` for an empty Observable.
  + *
  + * ```ts
  * import { EMPTY } from 'rxjs';
  * import { isEmpty } from 'rxjs/operators';
  *
  * const result = EMPTY.pipe(isEmpty());
  * result.subscribe(x => console.log(x));
  - * // Results in:
  + *
  + * // Outputs
  * // true
  * ```
  *
  * @see {@link count}
  - * @see {@link EMPTY}
  + * @see {@link index/EMPTY}
  *
  - * @return {OperatorFunction<T, boolean>} An Observable of a boolean value indicating whether observable was empty or not
  + * @return {OperatorFunction<T, boolean>} An Observable of a boolean value indicating whether observable was empty or not.
  * @method isEmpty
  * @owner Observable
  */
  