add auto voicechannel feature

[TomRomeo]

Hello! I really like this bot and wanted to contribute a feature. 😊
When I was checking out the discussions for possible features to implement, I came across the auto voicechannel feature.

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Short description of the feature:

Some voicechannels can be set as 'auto voicechannels'.
When a member joins this channel, a custom voicechannel will be created for them.
When they leave this channel, it gets removed again.

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For this feature I have implemented the following commands:

• autovc add #voicechannel
• autovc remove #voicechannel
• autovc purge
• autovc show

and the following permissions:

• sp.guild.config.autochannel
• sp.chat.autochannel

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The current behavior is the following:

• When someone joins an auto voicechannel, they get moved to a channel named after themselves.
• When they move or leave out of that channel, it gets deleted again.
• When they join the auto voicechannel from their custom vc, the custom vc gets removed but no new one is created.

Some things that might be nice to add:

• A possibility to rename the custom vcs might be nice? Or a prefix for custom vcs
• Some commands to lock the channel to a number of members or to add a whitelist might be nice
• Right now, the channels would not get removed when the bot goes offline, that is probably no great

Let me know what you think! 👋

[zekroTJA]

Man, that looks awesome. Thank you very much for the contribution! 😍

I will test around a bit with your implementation later today, but looks very good as what I've seen already.

[zekroTJA]

Found some things that might need a change, if you don't mind. ^^

If you have any questions or need some help for something, feel absolutely free to contact me on my Discord (zekro#0001) or Twitter or simply via mail. :)

[TomRomeo]

Hey! Thanks for the thorough review! 😄I will be working on your suggestions!

[zekroTJA]

Looks very goo.d Thank you for your awesome contribution. ^^