Add missing parameters to certain methods

- slowmode_delay and reason in Message.create_thread
- slowmode_delay in TextChannel.create_thread
- reason in Guild.edit_widget

discord/message.py

@@ -1595,7 +1595,14 @@ class Message(Hashable):
         """
         await self._state.http.clear_reactions(self.channel.id, self.id)
 
-    async def create_thread(self, *, name: str, auto_archive_duration: ThreadArchiveDuration = MISSING) -> Thread:
+    async def create_thread(
+        self,
+        *,
+        name: str,
+        auto_archive_duration: ThreadArchiveDuration = MISSING,
+        slowmode_delay: Optional[int] = None,
+        reason: Optional[str] = None,
+    ) -> Thread:
         """|coro|
 
         Creates a public thread from this message.
@@ -1614,6 +1621,12 @@ class Message(Hashable):
         auto_archive_duration: :class:`int`
             The duration in minutes before a thread is automatically archived for inactivity.
             If not provided, the channel's default auto archive duration is used.
+        slowmode_delay: Optional[:class:`int`]
+            Specifies the slowmode rate limit for user in this channel, in seconds.
+            The maximum value possible is `21600`. By default no slowmode rate limit
+            if this is ``None``.
+        reason: Optional[:class:`str`]
+            The reason for creating a new thread. Shows up on the audit log.
 
         Raises
         -------
@@ -1638,6 +1651,8 @@ class Message(Hashable):
             self.id,
             name=name,
             auto_archive_duration=auto_archive_duration or default_auto_archive_duration,
+            rate_limit_per_user=slowmode_delay,
+            reason=reason,
         )
         return Thread(guild=self.guild, state=self._state, data=data)