Explain RuntimeClass name in Pod Overhead concept (#45454)

* empty-commit

* changed_ex_kata_fc

* Update content/en/docs/concepts/scheduling-eviction/pod-overhead.md

Co-authored-by: Tim Bannister <tim@scalefactory.com>

* Update pod-overhead.md

---------

Co-authored-by: Tim Bannister <tim@scalefactory.com>

content/en/docs/concepts/scheduling-eviction/pod-overhead.md

@@ -36,9 +36,12 @@ You need to make sure a `RuntimeClass` is utilized which defines the `overhead`
 
 To work with Pod overhead, you need a RuntimeClass that defines the `overhead` field. As
 an example, you could use the following RuntimeClass definition with a virtualization container
-runtime that uses around 120MiB per Pod for the virtual machine and the guest OS:
+runtime (in this example, Kata Containers combined with the Firecracker virtual machine monitor)
+that uses around 120MiB per Pod for the virtual machine and the guest OS:
 
 ```yaml
+# You need to change this example to match the actual runtime name, and per-Pod
+# resource overhead, that the container runtime is adding in your cluster.
 apiVersion: node.k8s.io/v1
 kind: RuntimeClass
 metadata: