Add forum link to README

README.md

@@ -20,6 +20,7 @@ Traintastic is a client/server software application to control a model railway.
 
 The project goal is to develop open source software that can control everything in your model railway layout. More information can be found using the links below:
 
+- [Join the Traintastic forum](https://discourse.traintastic.org/)
 - [Download Traintastic](https://traintastic.org/download)
 - [Traintastic Manual](https://traintastic.org/manual)
 - [Traintastic hardware support](https://traintastic.org/supported-hardware)