Add link to MVP board

Author: zombiezen

CONTRIBUTING.md

@@ -8,6 +8,8 @@ If you're looking at contributing to the standard library,
 see the [standard library contributing guide](https://github.com/256lights/zb-stdlib/blob/main/CONTRIBUTING.md)
 and take a look at the [issues marked as good for newcomers](https://github.com/256lights/zb-stdlib/issues?q=is%3Aissue%20state%3Aopen%20label%3A%22good%20first%20issue%22).
 
+The current public roadmap is available on [GitHub Projects](https://github.com/orgs/256lights/projects/2).
+
 Contributors to zb must follow the [zb Code of Conduct](http://github.com/256lights/zb/blob/main/CODE_OF_CONDUCT.md).
 
 ## Improving the Documentation