attempt to remove plugin from docs (#1219)

The Kubernetes plugin is gone, this PR replaces the procedures that use
`kubectl minio` in all its various forms. The plugin was referenced on
many pages and for many purposes so there is _a lot_ of restructuring
involved.

Some procedures no longer have CLI instructions, which can be addressed
in subsequent PRs. Everything should have at least one working method,
even if it's to use Operator Console.

- Remove references to plugin, except for pre-4.5.8 upgrade paths
- Move pre-4.5.8 upgrade paths to new child page (currently hidden from
TOC, linked in page)
- Fill in with new Kustomize, kubectl, and/or Operator Console steps.

A handful of old screen captures still to be updated

Staged:
- [Operator
deploy](http://192.241.195.202:9000/staging/DOCS-1213-upstream/k8s/operations/installation.html)
- [Operator
upgrade](http://192.241.195.202:9000/staging/DOCS-1213-upstream/k8s/operations/install-deploy-manage/upgrade-minio-operator.html)
- [Deploy and manage
Tenants](http://192.241.195.202:9000/staging/DOCS-1213-upstream/k8s/operations/deploy-manage-tenants.html)

Fixes https://github.com/minio/docs/issues/1213

source/includes/container/steps-deploy-minio-single-node-single-drive.rst

@@ -89,7 +89,7 @@ The following table describes each line of the command and provides additional c
        Replace this value with the full path to a storage volume or folder on the local machine.
        For example:
 
-       Linux or MacOS
+       Linux or macOS
          ``~/minio/data/``
        
        Windows