Add hint to release-4.6 in README

We want to make sure people use the branch we have tested

README.md

@@ -1,3 +1,5 @@
+## Please note: if you are using OCP 4.6 please follow this [README](https://github.com/openshift/kata-operator/blob/release-4.6/README.md)
+
 # Kata Operator
 
 An operator to perform lifecycle management (install/upgrade/uninstall) of [Kata Runtime](https://katacontainers.io/) on Openshift as well as Kubernetes cluster.
@@ -111,4 +113,4 @@ Not implemented yet
 # Build from source
 
 1. Install operator-sdk version 1.0 or above
-2. make docker-build docker-push IMG=quay.io/<yourusername>/kata-operator:<tag>
+2. make docker-build docker-push IMG=quay.io/<yourusername>/kata-operator:<tag>