Fix and add documentation

discord/member.py

@@ -309,7 +309,7 @@ class Member(discord.abc.Messageable, _BaseUser):
         return try_enum(Status, self._client_status.get('web', 'offline'))
 
     def is_on_mobile(self):
-        """A helper function that determines if a member is active on a mobile device."""
+        """:class:`bool`: A helper function that determines if a member is active on a mobile device."""
         return 'mobile' in self._client_status
 
     @property
@@ -395,6 +395,11 @@ class Member(discord.abc.Messageable, _BaseUser):
         -----------
         message: :class:`Message`
             The message to check if you're mentioned in.
+
+        Returns
+        -------
+        :class:`bool`
+            Indicates if the member is mentioned in the message.
         """
         if message.guild is None or message.guild.id != self.guild.id:
             return False