Simple parser for WEBHOOKS_UPDATE

docs/api.rst

@@ -380,6 +380,12 @@ to handle it, which defaults to print a traceback and ignoring the exception.
     :param last_pin: A ``datetime.datetime`` object representing when the latest message
                      was pinned or ``None`` if there are no pins.
 
+.. function:: on_webhooks_update(channel)
+
+    Called whenever a webhook is created, modified, or removed from a guild channel.
+
+    :param channel: The :class:`abc.GuildChannel` that had it's webhooks updated.
+
 .. function:: on_member_join(member)
               on_member_remove(member)