Downstream Nix package on nixpkgs

[ToasterUwU]

I packaged this for Nix on nixpkgs, the timing of the provided nix packaging was kinda hilarious, was 90% done, refresh the repo and now there is a nix package that looks almost identical to mine.

Either way, its still a good thing to have and will make more things possible.

Here is the nixpkgs PR: NixOS/nixpkgs#486700

Whenever it gets merged it would be very nice to have something added to the README, something like "nixpkgs has a nix package, but if you want the absolutely newest version we provide our own package via a flake.nix as well"

[gerardbosch]

Heyyy, thanks! I tried to create the nixpkg too =)

But just closed my PR as duplicate, first time I tried to create a package for Nix. Let's hope your PR gets merged!

[ToasterUwU]

The nix package was merged and backported, so adding a README thing for that would now be possible