docs: Doc tweak

Author: Alan Christie

README.md

@@ -34,6 +34,7 @@ Prerequisites: -
 -   Python
 -   Docker
 -   A kubernetes config file
+-   A compatible Kubernetes (e.g. 1.23 if the operator is built for 1.22 thru 1.24)
 
 ## Contributing
 The project uses: -
@@ -68,7 +69,7 @@ is automatically built and pushed to Docker Hub using GitHub Actions.
 You can build and push the image yourself using docker-compose.
 The following will build an operator image with the tag `19.2.0-alpha.1`: -
 
-    export IMAGE_TAG=19.2.0-alpha.1
+    export IMAGE_TAG=23.1.0-alpha.1
     docker compose build
     docker compose push