Document how to provide a long announcement (EJAB-1553)

src/ejabberd_admin.erl

@@ -85,6 +85,10 @@ commands() ->
 			args = [], result = {res, rescode}},
      #ejabberd_commands{name = stop_kindly, tags = [server],
 			desc = "Inform users and rooms, wait, and stop the server",
+			longdesc = "Provide the delay in seconds, and the "
+			    "announcement quoted, for example: \n"
+			    "ejabberdctl stop_kindly 60 "
+			    "\\\"The server will stop in one minute.\\\"",
 			module = ?MODULE, function = stop_kindly,
 			args = [{delay, integer}, {announcement, string}],
 			result = {res, rescode}},