A nix flake is a reproducible way to describe the building process
to [nix](1).
See [the nix download page](1), on how to install nix. Afterwards
running `nix build` in the repository will result in a successful build.
Flakes and nix-commands are still experimental so they must be enabled
as described in [the corresponding wiki entry](2)
[1]: https://nixos.org/download.html#nix
[2]: https://nixos.wiki/wiki/Flakes#Enable_flakes.