Consolidate YAML files [part-4] (#9241)

This PR consolidates YAML files used in the
`tasks/debug-application-cluster` subdirectory.

Depends-On: #9236

content/en/examples/application/shell-demo.yaml

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: shell-demo
+spec:
+  volumes:
+  - name: shared-data
+    emptyDir: {}
+  containers:
+  - name: nginx
+    image: nginx
+    volumeMounts:
+    - name: shared-data
+      mountPath: /usr/share/nginx/html