psc: Update list description for security-discuss-private
psc: Update list description for security-discuss-private

Co-authored-by: Stephen Augustus <f96984fef9637085f0559f1484dfd4e99545cd6e@vmware.com>

kubernetes/k8s.io,kubernetes/k8s.io,thockin/k8s.io,thockin/k8s.io,thockin/k8s.io,kubernetes/k8s.io,thockin/k8s.io,kubernetes/k8s.io