Update 03-wls-operator.md

Author: Lily He

samples/kubernetes/end2end/docs/03-wls-operator.md

@@ -87,7 +87,7 @@ Verify that the domain CRD version is correct.
 ```
 kubectl get crd domains.weblogic.oracle -o jsonpath="{.spec.version}"
 ```
-The expected version should be `v5`. Since the WebLogic operator is backward compatible, domain resource with any version older than `v5` should be supported.
+The expected version should be `v5`. Because the WebLogic operator is backward compatible, a domain resource with any version older than `v5` should be supported.
 
 Now the WebLogic Kubernetes Operator is running and it's monitoring the default namespace. Later we'll deploy a domain resource to the default namespace and the operator will be responsible for creating, running, and managing the WebLogic domain.