Add integration with AdventOfCode.com site

[miwojc]

For the upcoming AdventOfCode 2021, which starts 1st December, we are going to have HS3 leaderboard for the event.

The below requirements are just an idea on how we could integrate AoC with HS3 discord via orpheus bot.

So one possibility would be to allow users to join AoC event and join our leaderboard (via leaderboard nubmer) directly from discord.

Then once user climbs the leaderboard, the bot could have a command to show position on leaderboard, or to show top10 leaderboard.

This would enhance experience of participating in AoC via our Discord :)

Let me know if you are interested in working on this (please note the above is just an idea of what's possible, once we work on this we can discover there are more things that are possible to integrate with AoC)