Update README

Author: shashankbarsin

README.md

@@ -4,7 +4,7 @@
 Acceptable values are latest or any semantic version string like 1.15.0. Use this action in workflow to define which version of kubectl will be used.
 
 ```yaml
-- uses: azure/k8s-actions/setup-kubectl@master
+- uses: azure/setup-kubectl@v1
   with:
     version: '<version>' # default is latest stable
   id: install