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* Update links to outdated user-guide and admin docs

* Add script for updating outdated links.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/concepts/configuration/assign-pod-node.md

@@ -6,7 +6,7 @@ assignees:
 title: Assigning Pods to Nodes
 ---
 
-You can constrain a [pod](/docs/user-guide/pods/) to only be able to run on particular [nodes](/docs/admin/node/) or to prefer to
+You can constrain a [pod](/docs/concepts/workloads/pods/pod/) to only be able to run on particular [nodes](/docs/concepts/nodes/node/) or to prefer to
 run on particular nodes. There are several ways to do this, and they all use
 [label selectors](/docs/user-guide/labels/) to make the selection.
 Generally such constraints are unnecessary, as the scheduler will automatically do a reasonable placement

docs/concepts/configuration/manage-compute-resources-container.md

@@ -242,7 +242,7 @@ system daemons use a portion of the available resources. The `allocatable` field
 gives the amount of resources that are available to Pods. For more information, see
 [Node Allocatable Resources](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/node-allocatable.md).
 
-The [resource quota](/docs/admin/resourcequota/) feature can be configured
+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.
 

docs/concepts/configuration/overview.md

@@ -39,8 +39,8 @@ This document is meant to highlight and consolidate in one place configuration b
 
 ## Services
 
-- It's typically best to create a [service](/docs/user-guide/services/) before corresponding [replication
-  controllers](/docs/user-guide/replication-controller/), so that the scheduler can spread the pods comprising the
+- It's typically best to create a [service](/docs/concepts/services-networking/service/) before corresponding [replication
+  controllers](/docs/concepts/workloads/controllers/replicationcontroller/), so that the scheduler can spread the pods comprising the
   service. You can also create a replication controller without specifying replicas (this will set
   replicas=1), create a service, then scale up the replication controller. This can be useful in
   ensuring that one replica works before creating lots of them.
@@ -50,8 +50,8 @@ This document is meant to highlight and consolidate in one place configuration b
   number of places that pod can be scheduled, due to port conflicts— you can only schedule as many
   such Pods as there are nodes in your Kubernetes cluster.
 
-  If you only need access to the port for debugging purposes, you can use the [kubectl proxy and apiserver proxy](/docs/user-guide/connecting-to-applications-proxy/) or [kubectl port-forward](/docs/user-guide/connecting-to-applications-port-forward/).
-  You can use a [Service](/docs/user-guide/services/) object for external service access.
+  If you only need access to the port for debugging purposes, you can use the [kubectl proxy and apiserver proxy](/docs/tasks/access-kubernetes-api/http-proxy-access-api/) or [kubectl port-forward](/docs/tasks/access-application-cluster/port-forward-access-application-cluster/).
+  You can use a [Service](/docs/concepts/services-networking/service/) object for external service access.
   If you do need to expose a pod's port on the host machine, consider using a [NodePort](/docs/user-guide/services/#type-nodeport) service before resorting to `hostPort`.
 
 - Avoid using `hostNetwork`, for the same reasons as `hostPort`.
@@ -78,7 +78,7 @@ This document is meant to highlight and consolidate in one place configuration b
   version-agnostic controller names. See the [documentation](/docs/tasks/run-application/rolling-update-replication-controller/) on
   the rolling-update command for more detail.
 
-  Note that the [Deployment](/docs/user-guide/deployments/) object obviates the need to manage replication
+  Note that the [Deployment](/docs/concepts/workloads/controllers/deployment/) object obviates the need to manage replication
   controller 'version names'. A desired state of an object is described by a Deployment, and if
   changes to that spec are _applied_, the deployment controller changes the actual state to the
   desired state at a controlled rate. (Deployment objects are currently part of the [`extensions`