Adding Galaxy badge to index

docs/index.md

@@ -1,4 +1,4 @@
-# Ansible Sensu
+# Ansible Sensu [![Ansible Galaxy](https://img.shields.io/badge/galaxy-cmacrae.sensu-660198.svg?style=flat)](https://galaxy.ansible.com/list#/roles/3802)
 An [Ansible](https://ansible.com) role that deploys a full [Sensu](https://sensuapp.org) stack, a modern, open source monitoring framework.
 
 ## Features