[Ur] NixOS package

[Sergey Mironov]

Hi. I noticed the 'Popular package systems' section on the main page.
Could you please add link to NixOS (www.nixos.org) package?

The binary url of a package:

http://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.urweb.x86_64-linux


Build rule (for reference) is on the GitHub
https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/compilers/urweb/default.nix

Regards,
Sergey