Revise Pod concept (#22603)

* Revise Pod concept

Adapt the existing Pod documentation to suit the Docsy theme, by
promoting the Pod concept itself to /docs/concepts/workloads/pods/

Following on from this, update the Pod Lifecycle page to cover the
lifecycle of a Pod and follow on directly from the Pod concept,
for readers keen to understand things in detail.

This change also removes the automatic contents list from the Pod
overview page. Instead, the new page links to all the pages
inside the Pod section.

* Update links to Pod concept

Link to updated content

* Incorporate Pod concept suggestions

Co-authored-by: Celeste Horgan <celeste@cncf.io>

* Revise StatefulSet suggestion for Pod concept

Co-authored-by: Celeste Horgan <celeste@cncf.io>

Co-authored-by: Celeste Horgan <celeste@cncf.io>

content/en/docs/tutorials/kubernetes-basics/deploy-app/deploy-interactive.html

@@ -20,7 +20,7 @@ weight: 20
         <div class="row">
             <div class="col-md-12">
                 <p>
-                    A Pod is the basic execution unit of a Kubernetes application. Each Pod represents a part of a workload that is running on your cluster. <a href="/docs/concepts/workloads/pods/pod-overview/#understanding-pods">Learn more about Pods</a>.
+                    A Pod is the basic execution unit of a Kubernetes application. Each Pod represents a part of a workload that is running on your cluster. <a href="/docs/concepts/workloads/pods/">Learn more about Pods</a>.
                 </p>
             </div>
         </div>

content/en/docs/tutorials/kubernetes-basics/expose/expose-intro.html

@@ -28,7 +28,7 @@ weight: 10
 			<div class="col-md-8">
 			<h3>Overview of Kubernetes Services</h3>
 
-			<p>Kubernetes <a href="/docs/concepts/workloads/pods/pod-overview/">Pods</a> are mortal. Pods in fact have a <a href="/docs/concepts/workloads/pods/pod-lifecycle/">lifecycle</a>. When a worker node dies, the Pods running on the Node are also lost. A <a href="/docs/concepts/workloads/controllers/replicaset/">ReplicaSet</a> might then dynamically drive the cluster back to desired state via creation of new Pods to keep your application running. As another example, consider an image-processing backend with 3 replicas. Those replicas are exchangeable; the front-end system should not care about backend replicas or even if a Pod is lost and recreated. That said, each Pod in a Kubernetes cluster has a unique IP address, even Pods on the same Node, so there needs to be a way of automatically reconciling changes among Pods so that your applications continue to function.</p>
+			<p>Kubernetes <a href="/docs/concepts/workloads/pods/">Pods</a> are mortal. Pods in fact have a <a href="/docs/concepts/workloads/pods/pod-lifecycle/">lifecycle</a>. When a worker node dies, the Pods running on the Node are also lost. A <a href="/docs/concepts/workloads/controllers/replicaset/">ReplicaSet</a> might then dynamically drive the cluster back to desired state via creation of new Pods to keep your application running. As another example, consider an image-processing backend with 3 replicas. Those replicas are exchangeable; the front-end system should not care about backend replicas or even if a Pod is lost and recreated. That said, each Pod in a Kubernetes cluster has a unique IP address, even Pods on the same Node, so there needs to be a way of automatically reconciling changes among Pods so that your applications continue to function.</p>
 
 			<p>A Service in Kubernetes is an abstraction which defines a logical set of Pods and a policy by which to access them. Services enable a loose coupling between dependent Pods. A Service is defined using YAML <a href="/docs/concepts/configuration/overview/#general-configuration-tips">(preferred)</a> or JSON, like all Kubernetes objects. The set of Pods targeted by a Service is usually determined by a <i>LabelSelector</i> (see below for why you might want a Service without including <code>selector</code> in the spec).</p>