docs(index): fix docs Rx.Scheduler.async is deprecated (#5231)
docs(index): fix docs Rx.Scheduler.async is deprecated (#5231)

* docs(index): fix docs error

* docs(bindCallback): Fix issues with example

Co-authored-by: Ben Lesh <73675debcd8a436be48ec22211dcf44fe0df0a64@benlesh.com>

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