Push swap project in School 21
Subject: https://cdn.intra.42.fr/pdf/pdf/4744/push_swap.en.pdf
https://afteracademy.com/blog/sort-a-stack-using-another-stack
https://medium.com/@jamierobertdawson/push-swap-the-least-amount-of-moves-with-two-stacks-d1e76a71789a