Update CONTRIBUTING with link to Getting Started

Issue spring-projectsgh-73

Author: jgrandja

CONTRIBUTING.adoc

@@ -1,7 +1,7 @@
 = Contributing to Spring Authorization Server
 
 Spring Authorization Server is released under the Apache 2.0 license.
-If you would like to contribute something, or simply want to hack on the code this document should help you get started.
+If you would like to contribute something, or simply want to hack on the code this document should help you https://github.com/spring-projects-experimental/spring-authorization-server#getting-started[get started].
 
 == Code of Conduct
 This project adheres to the Contributor Covenant link:CODE_OF_CONDUCT.adoc[code of conduct].