Merge pull request #123 from vayan/add-doc-link

Add a link to the documentation in the README

README.md

@@ -1,2 +1,6 @@
 [![GoDoc](http://godoc.org/github.com/robfig/cron?status.png)](http://godoc.org/github.com/robfig/cron) 
 [![Build Status](https://travis-ci.org/robfig/cron.svg?branch=master)](https://travis-ci.org/robfig/cron)
+
+# cron
+
+Documentation here: https://godoc.org/github.com/robfig/cron