Add to package managers

[Cretezy]

• [ ] Brew
• [x] WinGet: winget install Cretezy.lazyjj
• [x] Arch: pacman -S lazyjj (thanks @orhun!)
• [ ] Nixpkgs (help wanted!)

[maralorn]

I volunteer to package for nixpkgs. Sadly I think that will require moving away from rust-nightly, but I am trying to figure that out.

[orhun]

@maralorn see #41