Run black on all examples and require it for CI

examples/guessing_game.py

@@ -4,6 +4,7 @@ import discord
 import random
 import asyncio
 
+
 class MyClient(discord.Client):
     async def on_ready(self):
         print(f'Logged in as {self.user} (ID: {self.user.id})')
@@ -32,6 +33,7 @@ class MyClient(discord.Client):
             else:
                 await message.channel.send(f'Oops. It is actually {answer}.')
 
+
 intents = discord.Intents.default()
 intents.message_content = True