Add rules_scala support channels to readme (#1244)

Author: liucijus

README.md

@@ -1,5 +1,10 @@
 # Scala Rules for Bazel
-[![Build status](https://badge.buildkite.com/90ce5244556df74db805a3c24a703fb87458396f9e1ddd687e.svg?branch=master)](https://buildkite.com/bazel/scala-rules-scala-postsubmit) [![Gitter chat](https://badges.gitter.im/gitterHQ/gitter.png)](https://gitter.im/bazelbuild_rules_scala/Lobby)
+[![Build status](https://badge.buildkite.com/90ce5244556df74db805a3c24a703fb87458396f9e1ddd687e.svg?branch=master)](https://buildkite.com/bazel/scala-rules-scala-postsubmit) 
+
+## Where to get help
+ - [#scala @ Bazel Slack](https://bazelbuild.slack.com/archives/CDCKJ2KFZ)
+ - [Google group](https://groups.google.com/u/1/g/bazel-scala)
+ - [Gitter chat](https://gitter.im/bazelbuild_rules_scala/Lobby)
 
 ## Overview