chore: Add supported K8s and OpenShift section to release template

Author: Techassi

modules/ROOT/partials/release-notes/release-template.adoc

@@ -43,8 +43,24 @@ The following product versions are no longer supported (although images for rele
 
 ==== Supported Kubernetes versions
 
+This release supports the following Kubernetes versions:
+
+* `1.XX`
+
+These Kubernetes versions are no longer supported:
+
+* `1.XX`
+
 ==== Supported OpenShift versions
 
+This release is available in the RedHat Certified Operator Catalog for the following OpenShift versions:
+
+* `4.XX`
+
+These OpenShift versions are no longer supported:
+
+* `4.XX`
+
 ==== Breaking changes
 
 Of the changes mentioned above, the following are breaking (or could lead to breaking behaviour), and you will need to adapt your existing CRDs accordingly: