README.md: add code triagers badge

README.md

@@ -1,6 +1,7 @@
 [<img src="http://nixos.org/logo/nixos-hires.png" width="500px" alt="logo" />](https://nixos.org/nixos)
 
 [![Build Status](https://travis-ci.org/NixOS/nixpkgs.svg?branch=master)](https://travis-ci.org/NixOS/nixpkgs)
+[![Code Triagers Badge](https://www.codetriage.com/nixos/nixpkgs/badges/users.svg)](https://www.codetriage.com/nixos/nixpkgs)
 [![Issue Stats](http://www.issuestats.com/github/nixos/nixpkgs/badge/pr?style=flat)](http://www.issuestats.com/github/nixos/nixpkgs)
 [![Issue Stats](http://www.issuestats.com/github/nixos/nixpkgs/badge/issue?style=flat)](http://www.issuestats.com/github/nixos/nixpkgs)