docs(operators): add missing import to the example (#4638)
docs(operators): add missing import to the example (#4638)

* docs(operators): add missing import to the example

mergeScan import was missing in the example so it did not work

* docs(example): comment out expected result

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