Add Chef Supermarket and StackStorm Slack #community badges (#23)

Link to Supermarket and StackStorm Slack #community

Author: armab

README.md

@@ -1,6 +1,8 @@
 # StackStorm chef cookbook
 
 [![Build Status](https://travis-ci.org/StackStorm/chef-stackstorm.svg)](https://travis-ci.org/StackStorm/chef-stackstorm)
+[![Chef cookbook at Supermarket](https://img.shields.io/cookbook/v/stackstorm.svg?maxAge=2592000)](https://supermarket.chef.io/cookbooks/stackstorm)
+[![Join our community Slack](https://stackstorm-community.herokuapp.com/badge.svg)](https://stackstorm.typeform.com/to/K76GRP)
 
 Cookbook for [StackStorm](http://www.stackstorm.com) Automation as a Service. This cookbook is used to install and bring up **St2** components using Chef.