Add Nix packaging

[NelsonVides]

Description

Nixpgks is the largest and most up-to-date package manager in the world, and a good distribution point for new programs, to which this CLI is a perfect candidate. By providing a package for this environment, we can also assist customers automating Ops.

Expected Behavior or Outcome

• This CLI can be used in Nix environments

Acceptance Criteria

• Users can install this CLI using derivations
• Users can install this CLI using Nix flakes

As a stretch goal, package is published in https://search.nixos.org/packages with automatic versioning and users can install from there, but that'd require this repository be made public first.

Resources/References

• https://nix.dev/manual/nix/2.25/language/derivations
• https://nixos.wiki/wiki/Flakes

Notes

N/A

[NelsonVides]

@weppos, low priority questions in order to add NixOS support eventually. I've updated the PR linked, and also, now that the repo is public, we can also add it to https://github.com/NixOS/nixpkgs. That one has automation for updates when new releases in GitHub are created, so it should go maintenance-free in the future. Only thing is, it will require adding a maintainer in GitHub. Who would be best, do we have an "ops" account to tag? Or should we put a few of us there (and who)?