Add description of checks

Author: eheydrick

README.md

@@ -1,6 +1,6 @@
 ## Sensu-Plugins-Zookeeper
 
-[ ![Build Status](https://travis-ci.org/sensu-plugins/sensu-plugins-zookeeper.svg?branch=master)](https://travis-ci.org/sensu-plugins/sensu-plugins-zookeeper)
+[![Build Status](https://travis-ci.org/sensu-plugins/sensu-plugins-zookeeper.svg?branch=master)](https://travis-ci.org/sensu-plugins/sensu-plugins-zookeeper)
 [![Gem Version](https://badge.fury.io/rb/sensu-plugins-zookeeper.svg)](http://badge.fury.io/rb/sensu-plugins-zookeeper)
 [![Code Climate](https://codeclimate.com/github/sensu-plugins/sensu-plugins-zookeeper/badges/gpa.svg)](https://codeclimate.com/github/sensu-plugins/sensu-plugins-zookeeper)
 [![Test Coverage](https://codeclimate.com/github/sensu-plugins/sensu-plugins-zookeeper/badges/coverage.svg)](https://codeclimate.com/github/sensu-plugins/sensu-plugins-zookeeper)
@@ -10,6 +10,13 @@
 
 ## Files
 
+* check-znode.rb - Check if zookeeper znode exists and optionally match its contents
+* check-zookeeper-file-descriptors.rb - Check if Zookeeper has normal opened file descriptors rate
+* check-zookeeper-latency.rb - Check average latency on Zookeeper node
+* check-zookeeper-reqs.rb - Check if Zookeeper node has reliable number of outstanding requests
+* check-zookeeper-ruok.rb - Check if Zookeeper node responds to 'ruok' query succesfully
+* metrics-zookeeper.rb - Gather metrics from Zookeeper
+
 ## Usage
 
 ## Installation