message: docs(operator): add catchError to docs website
diff: @@ -7,6 +7,9 @@ import { InnerSubscriber } from '../InnerSubscriber';
  import {subscribeToResult} from '../util/subscribeToResult';
  import {ObservableInput, OperatorFunction, MonoTypeOperatorFunction} from '../types';
  +export function catchError<T>(selector: (err: any, caught: Observable<T>) => never): MonoTypeOperatorFunction<T>;
  +export function catchError<T, R>(selector: (err: any, caught: Observable<T>) => ObservableInput<R>): OperatorFunction<T, T | R>;
  +
  /**
  * Catches errors on the observable to be handled by returning a new observable or throwing an error.
  *
  @@ -74,8 +77,6 @@ import {ObservableInput, OperatorFunction, MonoTypeOperatorFunction} from '../ty
  * catch `selector` function.
  * @name catchError
  */
  -export function catchError<T>(selector: (err: any, caught: Observable<T>) => never): MonoTypeOperatorFunction<T>;
  -export function catchError<T, R>(selector: (err: any, caught: Observable<T>) => ObservableInput<R>): OperatorFunction<T, T | R>;
  export function catchError<T, R>(selector: (err: any, caught: Observable<T>) => ObservableInput<R>): OperatorFunction<T, T | R> {
  return function catchErrorOperatorFunction(source: Observable<T>): Observable<T | R> {
  const operator = new CatchOperator(selector);
  