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* Update links to outdated user-guide and admin docs

* Add script for updating outdated links.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/overview/components.md

@@ -87,7 +87,7 @@ See [here](http://releases.k8s.io/HEAD/cluster/addons) for more details.
 #### DNS
 
 While the other addons are not strictly required, all Kubernetes
-clusters should have [cluster DNS](/docs/admin/dns/), as many examples rely on it.
+clusters should have [cluster DNS](/docs/concepts/services-networking/dns-pod-service/), as many examples rely on it.
 
 Cluster DNS is a DNS server, in addition to the other DNS server(s) in your
 environment, which serves DNS records for Kubernetes services.

docs/concepts/overview/what-is-kubernetes.md

@@ -66,18 +66,18 @@ At a minimum, Kubernetes can schedule and run application containers on clusters
 
 Kubernetes satisfies a number of common needs of applications running in production, such as:
 
-* [co-locating helper processes](/docs/user-guide/pods/), facilitating composite applications and preserving the one-application-per-container model,
+* [co-locating helper processes](/docs/concepts/workloads/pods/pod/), facilitating composite applications and preserving the one-application-per-container model,
 * [mounting storage systems](/docs/concepts/storage/volumes/),
-* [distributing secrets](/docs/user-guide/secrets/),
+* [distributing secrets](/docs/concepts/configuration/secret/),
 * [application health checking](/docs/user-guide/production-pods/#liveness-and-readiness-probes-aka-health-checks),
-* [replicating application instances](/docs/user-guide/replication-controller/),
-* [horizontal auto-scaling](/docs/user-guide/horizontal-pod-autoscaling/),
-* [naming and discovery](/docs/user-guide/connecting-applications/),
-* [load balancing](/docs/user-guide/services/),
+* [replicating application instances](/docs/concepts/workloads/controllers/replicationcontroller/),
+* [horizontal auto-scaling](/docs/tasks/run-application/horizontal-pod-autoscale/),
+* [naming and discovery](/docs/concepts/services-networking/connect-applications-service/),
+* [load balancing](/docs/concepts/services-networking/service/),
 * [rolling updates](/docs/tasks/run-application/rolling-update-replication-controller/),
-* [resource monitoring](/docs/user-guide/monitoring/),
-* [log access and ingestion](/docs/user-guide/logging/overview/),
-* [support for introspection and debugging](/docs/user-guide/introspection-and-debugging/), and
+* [resource monitoring](/docs/concepts/cluster-administration/resource-usage-monitoring/),
+* [log access and ingestion](/docs/concepts/clusters/logging/),
+* [support for introspection and debugging](/docs/tasks/debug-application-cluster/debug-application-introspection/), and
 * [identity and authorization](/docs/admin/authorization/).
 
 This provides the simplicity of Platform as a Service (PaaS) with the flexibility of Infrastructure as a Service (IaaS), and facilitates portability across infrastructure providers.
@@ -88,7 +88,7 @@ For more details, see the [user guide](/docs/user-guide/).
 
 Even though Kubernetes provides a lot of functionality, there are always new scenarios that would benefit from new features. Application-specific workflows can be streamlined to accelerate developer velocity. Ad hoc orchestration that is acceptable initially often requires robust automation at scale. This is why Kubernetes was also designed to serve as a platform for building an ecosystem of components and tools to make it easier to deploy, scale, and manage applications.
 
-[Labels](/docs/user-guide/labels/) empower users to organize their resources however they please. [Annotations](/docs/user-guide/annotations/) enable users to decorate resources with custom information to facilitate their workflows and provide an easy way for management tools to checkpoint state.
+[Labels](/docs/user-guide/labels/) empower users to organize their resources however they please. [Annotations](/docs/concepts/overview/working-with-objects/annotations/) enable users to decorate resources with custom information to facilitate their workflows and provide an easy way for management tools to checkpoint state.
 
 Additionally, the [Kubernetes control plane](/docs/admin/cluster-components) is built upon the same [APIs](/docs/api/) that are available to developers and users. Users can write their own controllers, [schedulers](https://github.com/kubernetes/kubernetes/tree/{{page.githubbranch}}/docs/devel/scheduler.md), etc., if they choose, with [their own APIs](https://github.com/kubernetes/kubernetes/blob/{{page.githubbranch}}/docs/design/extending-api.md) that can be targeted by a general-purpose [command-line tool](/docs/user-guide/kubectl-overview/).
 

docs/concepts/overview/working-with-objects/labels.md

@@ -157,7 +157,7 @@ this selector (respectively in `json` or `yaml` format) is equivalent to `compon
 
 #### Resources that support set-based requirements
 
-Newer resources, such as [`Job`](/docs/concepts/jobs/run-to-completion-finite-workloads/), [`Deployment`](/docs/user-guide/deployments/), [`Replica Set`](/docs/user-guide/replicasets/), and [`Daemon Set`](/docs/admin/daemons/), support _set-based_ requirements as well.
+Newer resources, such as [`Job`](/docs/concepts/jobs/run-to-completion-finite-workloads/), [`Deployment`](/docs/concepts/workloads/controllers/deployment/), [`Replica Set`](/docs/concepts/workloads/controllers/replicaset/), and [`Daemon Set`](/docs/concepts/workloads/controllers/daemonset/), support _set-based_ requirements as well.
 
 ```yaml
 selector:

docs/concepts/overview/working-with-objects/namespaces.md

@@ -18,7 +18,7 @@ need the features they provide.
 
 Namespaces provide a scope for names.  Names of resources need to be unique within a namespace, but not across namespaces.
 
-Namespaces are a way to divide cluster resources between multiple uses (via [resource quota](/docs/admin/resourcequota/)).
+Namespaces are a way to divide cluster resources between multiple uses (via [resource quota](/docs/concepts/policy/resource-quotas/)).
 
 In future versions of Kubernetes, objects in the same namespace will have the same
 access control policies by default.