Update cheatsheet.md

Added another useful command for obtaining shell access to a running k8s pod.

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

@@ -311,6 +311,7 @@ kubectl run nginx --image=nginx                     # Run pod nginx and write it
 kubectl attach my-pod -i                            # Attach to Running Container
 kubectl port-forward my-pod 5000:6000               # Listen on port 5000 on the local machine and forward to port 6000 on my-pod
 kubectl exec my-pod -- ls /                         # Run command in existing pod (1 container case)
+kubectl exec --stdin --tty my-pod -- /bin/bash      # Get active shell access to a running pod (1 container case) 
 kubectl exec my-pod -c my-container -- ls /         # Run command in existing pod (multi-container case)
 kubectl top pod POD_NAME --containers               # Show metrics for a given pod and its containers
 ```