add example to readme;

Author: vietnogi

README.md

@@ -4,6 +4,11 @@
 [![Coverage Status](https://coveralls.io/repos/appirio-tech/ng-submit-work/badge.svg?branch=master&service=github)](https://coveralls.io/github/appirio-tech/ng-submit-work?branch=master)
 [![Dependency Status](https://www.versioneye.com/user/projects/55cbc568dfed0a001e000388/badge.svg?style=flat)](https://www.versioneye.com/user/projects/55cbc568dfed0a001e000388)
 
+## Example
+```jade
+submit-work(work-id="123")
+```
+
 ## Docs
 ### API