docs: Dynamically render latest image tag in docs (#735)
docs: Dynamically render latest image tag in docs (#735)

This change displays the latest image tag for the function in the
function doc page. This is intended as a convenience for users
to discover the full tag of the latest function image.
GoogleContainerTools/kpt-functions-catalog,GoogleContainerTools/kpt-functions-catalog,GoogleContainerTools/kpt-functions-catalog,GoogleContainerTools/kpt-functions-catalog,GoogleContainerTools/kpt-functions-catalog