Make `!source` a slash command

[DMFriends]

I think the !source command should be made a slash command because, similarly to the reason why we made !tags a slash command, it would make it easier to look up the name of a cog without having to leave the Discord channel if you don't exactly remember the name offhand. Note: I'm fine with someone else implementing this if approved, I don't really have the time right now to contribute at all

[Robin5605]

I assume we'd also implement autocomplete here?

[DMFriends]

Yes, that's what I was referring to when I said "it would make it easier to look up the name of a cog", just didn't have the word "autocomplete" offhand when I wrote the issue.

[mbaruh]

Sounds fine to me, although the cog would need to go through some structural changes to support auto-complete. Technically it could produce a static mapping of all possible terms and their appropriate info (type, link etc.), since I don't see why it would change without the bot restarting in the process. It would have to be the last cog to be loaded though, or there would have to be some other mechanic that would allow the mapping to fill up.

[Ibrahim2750mi]

Can I be assigned this?

[mbaruh]

Assigned