“ The Court of Appeals has a rule that counsel appointed for indigent appellants must, after adverse decision in the Court of Appeals, inform his client of the right to seek review in this Court and, if the client so desires, prepare a petition for certiorari. In denying Doherty's motion for counsel, the Court of Appeals apparently determined that its rule was of no help to Doherty, whose counsel had been retained rather than appointed. We defer to that court's construction of its own rule. ”