Allow creating gdms with one user

discord/client.py

@@ -3147,13 +3147,10 @@ class Client:
         -----------
         \*recipients: :class:`~discord.abc.Snowflake`
             An argument :class:`list` of :class:`discord.User` to have in
-            your group. Groups cannot be created with only one person,
-            but they can be created with zero people.
+            your group.
 
         Raises
         -------
-        TypeError
-            Only one recipient was given.
         HTTPException
             Failed to create the group direct message.
 
@@ -3162,11 +3159,13 @@ class Client:
         :class:`.GroupChannel`
             The new group channel.
         """
-        if len(recipients) == 1:
-            raise TypeError('Cannot create a group with only one recipient')
+        state = self._connection
 
         users: List[_Snowflake] = [u.id for u in recipients]
-        state = self._connection
+        if len(users) == 1:
+            # To create a group DM with one user, the client user must be included
+            users.append(state.self_id)  # type: ignore # user is always present when logged in
+
         data = await state.http.start_group(users)
         return GroupChannel(me=self.user, data=data, state=state)  # type: ignore # user is always present when logged in