(help-for-help): Doc fix.

lisp/help.el

@@ -253,7 +253,7 @@ of the key sequence that ran this command."
     (print-help-return-message)))
 
 (make-help-screen help-for-help
-  "a b c f C-f i k C-k l m n p s t v w C-c C-d C-n C-w.  Type \\[help-command] again for more help: "
+  "a b c f C-f i k C-k l m n p s t v w C-c C-d C-n C-w, or ? for more help:"
   "You have typed \\[help-command], the help character.  Type a Help option:
 \(Use \\[scroll-up] or \\[scroll-down] to scroll through this text.)