message: docs(concatMap): remove the unused tag
diff: @@ -58,9 +58,6 @@ export function concatMap<T, I, R>(this: Observable<T>, project: (value: T, inde
  * - `innerValue`: the value that came from the projected Observable
  * - `outerIndex`: the "index" of the value that came from the source
  * - `innerIndex`: the "index" of the value from the projected Observable
  - * @return {Observable} An observable of values merged from the projected
  - * Observables as they were subscribed to, one at a time. Optionally, these
  - * values may have been projected from a passed `projectResult` argument.
  * @return {Observable} An Observable that emits the result of applying the
  * projection function (and the optional `resultSelector`) to each item emitted
  * by the source Observable and taking values from each projected inner
  