Merge branch 'feature/slash' into conflict

Author: BobDotCom

.gitignore

@@ -14,3 +14,4 @@ docs/crowdin.py
 *.jpg
 *.flac
 *.mo
+.idea/

discord/__init__.py

@@ -61,6 +61,7 @@
 from .threads import *
 from .bot import *
 from .app import *
+from .cog import Cog
 from .welcome_screen import *
 
 

discord/abc.py

@@ -62,6 +62,7 @@
     'GuildChannel',
     'Messageable',
     'Connectable',
+    'Mentionable'
 )
 
 T = TypeVar('T', bound=VoiceProtocol)
@@ -1141,6 +1142,7 @@ class Messageable:
     - :class:`~discord.Member`
     - :class:`~discord.ext.commands.Context`
     - :class:`~discord.Thread`
+    - :class:`~discord.ApplicationContext`
     """
 
     __slots__ = ()
@@ -1690,4 +1692,4 @@ async def connect(
 
 class Mentionable:
     # TODO: documentation, methods if needed
-    pass
+    pass