on user join discord.py code example

Example 1: how to mention someone discord.py

myid = '<@201909896357216256>'
await client.send_message(message.channel, ' : %s is the best ' % myid)

Example 2: discord py join and leave call

# Join command, joins the voice channel of whoever sent the command
@bot.command()
	async def join(context):
        channel = context.author.voice.channel
        await channel.connect()

# Leave command, leaves the voice channel
@bot.command()
    async def leave(context):
        await context.voice_client.disconnect()

# Note that these are made to be run in main and not a cog, 
# will still work in cog with minor edits