Add Nix to installation instructions
Add Nix to installation instructions

Not sure how to compare speed and freshness, but IMO nixpkgs is usually faster to update the registry than e.g. brew.

macOS installation doesn't work yet (https://github.com/NixOS/nixpkgs/pull/89527), but should be fine on Linux distros.
dflemstr/rq,dflemstr/rq