doc: clean up the federation and kubefed(federation v1 cli) references. (#19583)

content/en/docs/concepts/cluster-administration/cluster-administration-overview.md

@@ -20,7 +20,6 @@ See the guides in [Setup](/docs/setup/) for examples of how to plan, set up, and
 Before choosing a guide, here are some considerations:
 
  - Do you just want to try out Kubernetes on your computer, or do you want to build a high-availability, multi-node cluster? Choose distros best suited for your needs.
- - **If you are designing for high-availability**, learn about configuring [clusters in multiple zones](/docs/concepts/cluster-administration/federation/).
  - Will you be using **a hosted Kubernetes cluster**, such as [Google Kubernetes Engine](https://cloud.google.com/kubernetes-engine/), or **hosting your own cluster**?
  - Will your cluster be **on-premises**, or **in the cloud (IaaS)**? Kubernetes does not directly support hybrid clusters. Instead, you can set up multiple clusters.
  - **If you are configuring Kubernetes on-premises**, consider which [networking model](/docs/concepts/cluster-administration/networking/) fits best.

content/en/docs/reference/tools.md

@@ -18,11 +18,6 @@ Kubernetes contains several built-in tools to help you work with the Kubernetes
 
 [`kubeadm`](/docs/setup/production-environment/tools/kubeadm/install-kubeadm/) is the command line tool for easily provisioning a secure Kubernetes cluster on top of physical or cloud servers or virtual machines (currently in alpha).
 
-## Kubefed
-
-[`kubefed`](/docs/tasks/federation/set-up-cluster-federation-kubefed/) is the command line tool
-to help you administrate your federated clusters.
-
 ## Minikube
 
 [`minikube`](/docs/tasks/tools/install-minikube/) is a tool that makes it

content/en/docs/tasks/debug-application-cluster/debug-cluster.md

@@ -124,7 +124,4 @@ This is an incomplete list of things that could go wrong, and how to adjust your
   - Mitigates: Node shutdown
   - Mitigates: Kubelet software fault
 
-- Action: [Multiple independent clusters](/docs/concepts/cluster-administration/federation/) (and avoid making risky changes to all clusters at once)
-  - Mitigates: Everything listed above.
-
 {{% /capture %}}