docs(OperatorSubscriber): add comments
docs(OperatorSubscriber): add comments

kwonoj/RxJS,ReactiveX/rxjs,martinsik/rxjs,ReactiveX/RxJS,benlesh/RxJS,kwonoj/RxJS,ReactiveX/RxJS,kwonoj/RxJS,martinsik/rxjs,martinsik/rxjs,ReactiveX/rxjs,martinsik/rxjs,benlesh/RxJS,ReactiveX/rxjs,kwonoj/RxJS,ReactiveX/RxJS,ReactiveX/rxjs,benlesh/RxJS,benlesh/RxJS,ReactiveX/RxJS