Add message content to the Intents.default docstring

discord/flags.py

@@ -509,7 +509,7 @@ class Intents(BaseFlags):
     @classmethod
     def default(cls: Type[Intents]) -> Intents:
         """A factory method that creates a :class:`Intents` with everything enabled
-        except :attr:`presences` and :attr:`members`.
+        except :attr:`presences`, :attr:`members`, and :attr:`message_content`.
         """
         self = cls.all()
         self.presences = False