message: docs(startWith-operator): add description and example for startWith operator
  improve documentation of startWith operator by adding usage examples and an alternative description
  of the behavior
  none
diff: @@ -20,8 +20,26 @@ export function startWith<T>(...array: Array<T | SchedulerLike>): MonoTypeOperat
  * Returns an Observable that emits the items you specify as arguments before it begins to emit
  * items emitted by the source Observable.
  *
  + * <span class="informal">First emits its arguments in order, and then any
  + * emissions from the source.</span>
  + *
  * ![](startWith.png)
  *
  + * ## Examples
  + *
  + * Start the chain of emissions with `"first"`, `"second"`
  + *
  + * ```javascript
  + * of("from source")
  + * .pipe(startWith("first", "second"))
  + * .subscribe(x => console.log(x));
  + *
  + * // results:
  + * // "first"
  + * // "second"
  + * // "from source"
  + * ```
  + *
  * @param {...T} values - Items you want the modified Observable to emit first.
  * @param {SchedulerLike} [scheduler] - A {@link SchedulerLike} to use for scheduling
  * the emissions of the `next` notifications.
  