Add Patricks fix

Author: qpetraroia

articles/aks/start-stop-nodepools.md

@@ -33,6 +33,12 @@ az extension update --name aks-preview
 az feature register --namespace "Microsoft.ContainerService" --name "PreviewStartStopAgentPool"
 ```
 
+It takes a few minutes for the status to show *Registered*. Verify the registration status by using the [az feature list][az-feature-list] command:
+
+```azurecli-interactive
+az feature list -o table --query "[?contains(name, 'Microsoft.ContainerService/PreviewStartStopAgentPool')].{Name:name,State:properties.state}"
+```
+
 When ready, refresh the registration of the *Microsoft.ContainerService* resource provider by using the [az provider register][az-provider-register] command:
 
 ```azurecli-interactive