Advent of Nim 2021

[pietroppeter]

It has been a long night but I have realized a dream I had from last year: 
listening to a puzzle input (using 
[paramidi](https://github.com/paranim/paramidi), thanks @sekao!). Enjoy [Whale 
Music 
🐳🎶](https://pietroppeter.github.io/adventofnim/2021/day03.html#whale_music)!