Add support doc (Azure#180)

Author: heaths

SUPPORT.md

@@ -0,0 +1,14 @@
+# Support
+
+## How to file issues and get help
+
+This project uses GitHub Issues to track bugs and feature requests. Please search the existing
+issues before filing new issues to avoid duplicates. For new issues, file your bug or
+feature request as a new Issue.
+
+For help and questions about using this product, please join the discussion on existing
+[issues](https://github.com/azure/azure-sdk-for-rust/issues) or create a new issue.
+
+## Microsoft Support Policy
+
+Support for this project is limited to the resources listed above.