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* Update links to outdated user-guide and admin docs

* Add script for updating outdated links.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/monitor-node-health.md

@@ -10,7 +10,7 @@ title: Monitoring Node Health
 
 ## Node Problem Detector
 
-*Node problem detector* is a [DaemonSet](/docs/admin/daemons/) monitoring the
+*Node problem detector* is a [DaemonSet](/docs/concepts/workloads/controllers/daemonset/) monitoring the
 node health. It collects node problems from various daemons and reports them
 to the apiserver as [NodeCondition](/docs/admin/node/#node-condition) and
 [Event](/docs/api-reference/v1.6/#event-v1-core).
@@ -120,7 +120,7 @@ Just create `node-problem-detector.yaml`, and put it under the addon pods direct
 The [default configuration](https://github.com/kubernetes/node-problem-detector/tree/v0.1/config)
 is embedded when building the docker image of node problem detector.
 
-However, you can use [ConfigMap](/docs/user-guide/configmap/) to overwrite it
+However, you can use [ConfigMap](/docs/tasks/configure-pod-container/configmap/) to overwrite it
 following the steps:
 
 * **Step 1:** Change the config files in `config/`.