Update custom-resource-definition-versioning.md

Since there can be only one version that needs to be stored and storage option is required else the parsing fails. Adding the storage option and setting it false.

Schema Vaildation fails with error: error validating data: ValidationError(CustomResourceDefinition.spec.versions[1]): missing
 required field "storage" in io.k8s.apiextensions-apiserver.pkg.apis.apiextensions.v1.CustomResourceDefinitionVersion; if you choose to
 ignore these errors, turn validation off with --validate=false

content/en/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definition-versioning.md

@@ -297,11 +297,13 @@ spec:
   versions:
   - name: v1alpha1
     served: true
+    storage: false
     # This indicates the v1alpha1 version of the custom resource is deprecated.
     # API requests to this version receive a warning header in the server response.
     deprecated: true
     # This overrides the default warning returned to API clients making v1alpha1 API requests.
     deprecationWarning: "example.com/v1alpha1 CronTab is deprecated; see http://example.com/v1alpha1-v1 for instructions to migrate to example.com/v1 CronTab"
+    
     schema: ...
   - name: v1beta1
     served: true
@@ -334,6 +336,7 @@ spec:
   versions:
   - name: v1alpha1
     served: true
+    storage: false
     # This indicates the v1alpha1 version of the custom resource is deprecated.
     # API requests to this version receive a warning header in the server response.
     deprecated: true