Revise cluster management task

After removing the sections of the page that are not in line with the
content guide, there is little left.

Edit pages that link to removed task to no longer link there.
Redirect using 302 status so that there is a future opportunity to reinstate
the page or something like it.

- Avoid links to removed cluster management task
- Broaden applicability of “Safely Drain A Node”
- Add (stub) cluster upgrade task page
- Add a basic page about upgrading your cluster.
- Add a task page about enabling or disabling HTTP APIs

content/en/docs/tasks/administer-cluster/enable-disable-api.md

@@ -0,0 +1,29 @@
+---
+title: Enable Or Disable A Kubernetes API
+content_type: task
+---
+
+<!-- overview -->
+This page shows how to enable or disable an API version from your cluster's
+{{< glossary_tooltip text="control plane" term_id="control-plane" >}}.
+
+<!-- steps -->
+
+
+Specific API versions can be turned on or off by passing `--runtime-config=api/<version>` as a
+command line argument to the API server. The values for this argument are a comma-separated
+list of API versions. Later values override earlier values.
+
+The `runtime-config` command line argument also supports 2 special keys:
+
+- `api/all`, representing all known APIs
+- `api/legacy`, representing only legacy APIs. Legacy APIs are any APIs that have been
+   explicitly [deprecated](/docs/reference/using-api/deprecation-policy/).
+
+For example, to turning off all API versions except v1, pass `--runtime-config=api/all=false,api/v1=true`
+to the `kube-apiserver`.
+
+## {{% heading "whatsnext" %}}
+
+Read the [full documentation](/docs/reference/command-line-tools-reference/kube-apiserver/)
+for the `kube-apiserver` component.