Add SUPPORT.md file

https://help.github.com/articles/adding-support-resources-to-your-project/

Author: danielcompton

SUPPORT.md

@@ -0,0 +1,5 @@
+## Support questions
+
+The Github issues are for bug reports and feature requests only. Support requests and usage
+questions should go to the re-frame [Clojure Slack channel](http://clojurians.net) or
+the [ClojureScript mailing list](https://groups.google.com/forum/#!forum/clojurescript).