Organize control plane update page (#3708)
Organize control plane update page (#3708)

* Organize control plane update page

* small wording

* typo

* Update content/docs/setup/kubernetes/upgrade/index.md

Co-Authored-By: linsun <438379232d6dc5f33cfee1346246b887b66cf53a@us.ibm.com>

* Update content/docs/setup/kubernetes/upgrade/index.md

Co-Authored-By: linsun <438379232d6dc5f33cfee1346246b887b66cf53a@us.ibm.com>

* address martin comment and hope to fix circleci

* more update

* fix circle lint

geeknoid/istio.github.io,geeknoid/istio.github.io,geeknoid/istio.github.io,istio/istio.io,geeknoid/istio.github.io,istio/istio.io,istio/istio.io,istio/istio.io,geeknoid/istio.github.io,istio/istio.io,istio/istio.io,istio/istio.io