Update cheatsheet.md

adding a custom output to format output by listing Images per Pod in table.

content/en/docs/reference/kubectl/cheatsheet.md

@@ -374,6 +374,8 @@ Examples using `-o=custom-columns`:
 ```bash
 # All images running in a cluster
 kubectl get pods -A -o=custom-columns='DATA:spec.containers[*].image'
+# All images running in namespace: default, grouped by Pod
+kubectl get pods --namespace default --output=custom-columns="NAME:.metadata.name,IMAGE:.spec.containers[*].image"
 
  # All images excluding "k8s.gcr.io/coredns:1.6.2"
 kubectl get pods -A -o=custom-columns='DATA:spec.containers[?(@.image!="k8s.gcr.io/coredns:1.6.2")].image'