Update App-of-Apps to use overlays

Author: gnunn1

content/modules/ROOT/pages/04-applicationsets.adoc

@@ -51,7 +51,15 @@ total 12
 -rw-r--r--. 1 lab-user 1001040000   0 Jul 29 21:54 kustomization.yaml
 ----
 
-There are three Applications defined, one for each environment, with kustomize being used to manage them.
+There are three Applications defined, one for each environment, with kustomize being used to manage them. If you look at each
+of these Applications note that each environment is tied to a different kustomize overlay matching the destination. This
+provides an opportunity to tweak the manifests for anything specific to an environment. For example, if you look at the overlays
+the `stage` and `prod` environments are patching the vertx-gateway deployment to have two replicas.
+
+[source,yaml,subs="+macros,attributes+"]
+----
+include::ROOT:example$coolstore/overlays/prod/kustomization.yaml[]
+----
 
 Proceed to deploy the app-of-apps Application:
 
@@ -76,8 +84,8 @@ Click on the `coolstore` tile, notice that it has three resources that it deploy
 
 image::app-of-apps-resources.png[]
 
-Now let's clean-up the Applications however before we do so, have a closer look at the `coolstore` App-of-Apps we deployed:
-[.console-output]
+Now before we clean-up the Applications have a closer look at the `coolstore` App-of-Apps we deployed:
+
 [source,yaml,subs="attributes+,+macros"]
 ----
 include::ROOT:example$app-of-apps/coolstore-app-of-apps.yaml[]
@@ -94,6 +102,16 @@ In this section we have seen how we can use App-of-Apps to deploy multiple Appli
 Applications is static, what if we want to create Applications dynamically based on external sources? This is where
 ApplicationSets come into play.
 
+Delete the Application:
+
+[.console-input]
+[source,yaml,subs="attributes",role=execute]
+----
+delete app coolstore -n {user}-argocd
+----
+
+Wait for all of the Applications to be removed from the Argo CD UI.
+
 == ApplicationSets
 
 As we saw previously, there are often situations where you want to deploy or generate multiple versions of the same Application with variations. These variations can be static,