Merge branch 'nixos-hardware-merge-preparations' into nixos-hardware-merge

Merges https://github.com/NixOS/nixos-hardware into nixpkgs.

This will give better discoverability, and considering the low
turnover (less than 100 commits in the last year and only 350 total)
it won’t make any dent on the size of nixpkgs.

We have a monorepo, let’s use it