Improvement for k8s.io/docs/tasks/configure-pod-container/configure-pod-configmap/

When skimming through this page I felt that I was missing the use case where we mount a single file from the configmap with a specific subpath that would not overwrite then entire specified folder as all example show in the "Add ConfigMap data to a Volume" section. It's the first thing that would come to my mind for using of a configmap after using it for containers environment and I don't see it described.
I'm not advocating that my experience and use of configmap is representative of everyone's or universal, but I though the feedback was worth sharing :)
Thank you for the amazing work on the doc!

Open k8s.io/docs/tasks/configure-pod-container/configure-pod-configmap/ and read the “Add ConfigMap data to a Volume” section first. Add an example covering a single ConfigMap file mounted with a specific subpath, and confirm the page explains that the existing directory contents are preserved.

Written by the indexing model from the issue text.