Update README.md

Author: rcastley

README.md

@@ -22,6 +22,6 @@ Unless required by applicable law or agreed to in writing, software distributed
 
 To get started, please proceed to [The Splunk Observability Cloud Workshops Homepage](https://splunk.github.io/observability-workshop/latest/).
 
-The latest versions of the workshop are:
-- [v5.29](https://splunk.github.io/observability-workshop/v5.29/)
-- [v5.28](https://splunk.github.io/observability-workshop/v5.28/)
+Latest versions of the workshop are:
+- [v5.30](https://splunk.github.io/observability-workshop/v5.29/)
+- [v5.29](https://splunk.github.io/observability-workshop/v5.28/)