Move to Concepts: Admin Overview. (#3698)

* Move to Concepts: Admin Overview.

* Fix filename.

_data/concepts.yml

@@ -48,6 +48,7 @@ toc:
 
 - title: Cluster Administration
   section:
+  - docs/concepts/cluster-administration/cluster-administration-overview.md
   - docs/concepts/cluster-administration/configure-etcd.md
   - docs/concepts/cluster-administration/etcd-upgrade.md
   - docs/concepts/cluster-administration/manage-deployment.md

_data/tasks.yml

@@ -98,7 +98,6 @@ toc:
   - docs/tasks/administer-cluster/cpu-memory-limit.md
   - docs/tasks/administer-cluster/reserve-compute-resources.md
   - docs/tasks/administer-cluster/guaranteed-scheduling-critical-addon-pods.md
-  - docs/tasks/administer-cluster/overview.md
   - docs/tasks/administer-cluster/upgrade-1-6.md
   - docs/tasks/administer-cluster/namespaces.md
   - docs/tasks/administer-cluster/namespaces-walkthrough.md

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

@@ -6,6 +6,8 @@ title: Cluster Administration Overview
 redirect_from:
 - "/docs/admin/"
 - "/docs/admin/index.html"
+- "/docs/tasks/administer-cluster/overview/"
+- "/docs/tasks/administer-cluster/overview.html"
 ---
 
 The cluster administration overview is for anyone creating or administering a Kubernetes cluster.