Add link to devdocs

README.md

@@ -67,6 +67,7 @@ An explanation of donation possibilities and usage of donations is available at
 
 ## Contributing
 
+[![dev-docs](https://img.shields.io/badge/dev-docs-blue)](https://devdocs.jabref.org/)
 [![Help Contribute to Open Source](https://www.codetriage.com/jabref/jabref/badges/users.svg)](https://www.codetriage.com/jabref/jabref)
 [![Join the chat at https://gitter.im/JabRef/jabref](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/JabRef/jabref?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![OpenHub](https://www.openhub.net/p/jabref/widgets/project_thin_badge.gif)](https://www.openhub.net/p/jabref)