Update User Guide and Admin links to point to new resources. (#3438)

* Update links to outdated user-guide and admin docs

* Add script for updating outdated links.

* Update regex to include init-containers file.

* Pull upstream, rewrite links in and to namespaces walkthrough.

docs/tasks/debug-application-cluster/debug-pod-replication-controller.md

@@ -48,7 +48,7 @@ case you can try several things:
         kubectl get nodes -o yaml | grep '\sname\|cpu\|memory'
         kubectl get nodes -o json | jq '.items[] | {name: .metadata.name, cap: .status.capacity}'
 
-  The [resource quota](/docs/admin/resourcequota/)
+  The [resource quota](/docs/concepts/policy/resource-quotas/)
   feature can be configured to limit the total amount of
   resources that can be consumed. If used in conjunction with namespaces, it can
   prevent one team from hogging all the resources.