[commands] Update Bot.command() decorator docs

discord/ext/commands/core.py

@@ -1237,6 +1237,11 @@ class GroupMixin:
     def command(self, *args, **kwargs):
         """A shortcut decorator that invokes :func:`.command` and adds it to
         the internal command list via :meth:`~.GroupMixin.add_command`.
+
+        Returns
+        --------
+        Callable[..., :class:`Command`]
+            A decorator that converts the provided method into a Command, adds it to the bot, then returns it
         """
         def decorator(func):
             kwargs.setdefault('parent', self)