* Remove doc on "Istio DNS Certificate Management"
This document gives harmful advice. This feature was intended to be used
for signing control plane certificates, and actually doesn't work for
other cases (cross namespace or any modern Kubernetes version are
completely broken).
* use archive link
* name trick
* Blog for Istio DNS certificate management
* Change the wording
* Add an explanation for the architecture
* Revise the wording
* Revisions based on review comments
* Fix a typo