Yes, go an sin no more is the watch-word. We might notice that the injunction relates to the future, not the past. Our Lord did not say to her that her previous sin cut her off from communion with Him, neither did He do what the Pharisees expected Him to do, which was to apply the Mosaic Law to her.
But, of course, Our Lord was not running an institution, so one might say that whereas He could dispense with a rule-book, His Church needs one. One might, however, add that Our Lord's words should provide the spirit which should infuse such rules.
In this is love, not that we loved God, but that He loved us and sent His Son to be the propitiation for our sins. (1 John 4:10)