Update README.md

Author: MichelLeBon

spring-rest/README.md

@@ -7,3 +7,4 @@
 - [Spring @RequestMapping](http://www.baeldung.com/spring-requestmapping)
 - [Http Message Converters with the Spring Framework](http://www.baeldung.com/spring-httpmessageconverter-rest)
 - [Redirect in Spring](http://www.baeldung.com/spring-redirect-and-forward)
+- [Returning Custom Status Codes from Spring Controllers](http://www.baeldung.com/spring-mvc-controller-custom-http-status-code)