Update README.md with apply clarification.

Update the kubectl apply commands in the customizing section to match those the quickstart section. The customizing section did not account for the recently introduced setup/ subdirectory.

README.md

@@ -236,8 +236,13 @@ The previous steps (compilation) has created a bunch of manifest files in the ma
 Now simply use `kubectl` to install Prometheus and Grafana as per your configuration:
 
 ```shell
+# Update the namespace and CRDs, and then wait for them to be availble before creating the remaining resources
+$ kubectl apply -f manifests/setup
 $ kubectl apply -f manifests/
 ```
+Alternatively, the resources in both folders can be applied with a single command 
+`kubectl apply -Rf manifests`, but it may be necessary to run the command multiple times for all components to
+be created successfullly.
 
 Check the monitoring namespace (or the namespace you have specific in `namespace: `) and make sure the pods are running. Prometheus and Grafana should be up and running soon.