Flake

[haras-unicorn]

I was going to add a package into nixpkgs for this but I realized the build step is a bit more complex than i liked so I went first to make this a flake and add a package via either cargo2nix or nixpkgs. This repo uses nix anyway and flakes are just a bit nicer way to setup a dev environment than just shell.nix IMO.

I am able to enter the shell but building with cargo gives me errors. It's rather long so I wont be posting that here.

I was not able to disable 32 bits for nixGL so I'd need a bit of help on that. I also replaced rustup with rustc and cargo since they're just faster to setup however that might lead to some issues.