Update Cake.XCode README: Add link to GitHub Discussions (Closes #18)

README.md

@@ -14,7 +14,11 @@ Please visit the Cake Documentation for a list of available aliases:
 
 http://cakebuild.net/dsl/xcode
 
+## Discussion
 
+For questions and to discuss ideas & feature requests, use the [GitHub discussions on the Cake GitHub repository](https://github.com/cake-build/cake/discussions), under the [Extension Q&A](https://github.com/cake-build/cake/discussions/categories/extension-q-a) category.
+
+[![Join in the discussion on the Cake repository](https://img.shields.io/badge/GitHub-Discussions-green?logo=github)](https://github.com/cake-build/cake/discussions)
 
 ## Apache License 2.0
 Apache Cake.Xamarin Copyright 2015. The Apache Software Foundation This product includes software developed at The Apache Software Foundation (http://www.apache.org/).