message: docs(skipWhile): add description and example for the operator
diff: @@ -9,6 +9,37 @@ import { OperatorSubscriber } from './OperatorSubscriber';
  *
  * ![](skipWhile.png)
  *
  + * Skips all the notifications with a truthy predicate. It will not skip the notifications when the predicate is falsy.
  + * It can also be skipped using index. Once the predicate is true, it will not be called again.
  + *
  + * ## Example
  + * Using Value: Skip some super heroes
  + * ```ts
  + * import { from } from 'rxjs';
  + * import { skipWhile } from 'rxjs/operators';
  + *
  + * const source = from(['Green Arrow', 'SuperMan', 'Flash', 'SuperGirl', 'Black Canary'])
  + * // Skip the heroes until SuperGirl
  + * const example = source.pipe(skipWhile((hero) => hero !== 'SuperGirl'));
  + * // output: SuperGirl, Black Canary
  + * example.subscribe((femaleHero) => console.log(femaleHero));
  + * ```
  + * Using Index: Skip value from the array until index 5
  + * ```ts
  + * import { from } from 'rxjs';
  + * import { skipWhile } from 'rxjs/operators';
  + *
  + * const source = from([1, 2, 3, 4, 5, 6, 7, 9, 10]);
  + * const example = source.pipe(skipWhile((_, i) => i !== 5));
  + * // output: 6, 7, 9, 10
  + * example.subscribe((val) => console.log(val));
  + * ```
  + *
  + * @see {@link last}
  + * @see {@link skip}
  + * @see {@link skipUntil}
  + * @see {@link skipLast}
  + *
  * @param {Function} predicate - A function to test each item emitted from the source Observable.
  * @return {Observable<T>} An Observable that begins emitting items emitted by the source Observable when the
  * specified predicate becomes false.
  