Fix some "capture prerequisites" errors in docs/tasks. (#10270)

Multiple "capture prerequisites" can only display the last one, so we need to
merge multiple "capture prerequisites".

content/en/docs/tasks/access-application-cluster/configure-access-multiple-clusters.md

@@ -22,14 +22,6 @@ It does not mean that there is a file named `kubeconfig`.
 
 {{% capture prerequisites %}}
 
-You need to have the [`kubectl`](/docs/tasks/tools/install-kubectl/) command-line tool installed.
-
-{{% /capture %}}
-
-{{< toc >}}
-
-{{% capture prerequisites %}}
-
 {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
 
 {{% /capture %}}

content/en/docs/tasks/access-kubernetes-api/setup-extension-api-server.md

@@ -16,15 +16,10 @@ Setting up an extension API server to work the aggregation layer allows the Kube
 
 {{% capture prerequisites %}}
 
-* You need to have a Kubernetes cluster running.
-* You must [configure the aggregation layer](/docs/tasks/access-kubernetes-api/configure-aggregation-layer/) and enable the apiserver flags.
-
-{{% /capture %}}
-
-{{% capture prerequisites %}}
-
 {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
 
+* You must [configure the aggregation layer](/docs/tasks/access-kubernetes-api/configure-aggregation-layer/) and enable the apiserver flags.
+
 {{% /capture %}}
 
 {{% capture steps %}}

content/en/docs/tasks/administer-cluster/declare-network-policy.md

@@ -9,22 +9,19 @@ content_template: templates/task
 This document helps you get started using the Kubernetes [NetworkPolicy API](/docs/concepts/services-networking/network-policies/) to declare network policies that govern how pods communicate with each other.
 {{% /capture %}}
 
-{{% capture prerequisites %}}
-You'll need to have a Kubernetes cluster in place, with network policy support. There are a number of network providers that support NetworkPolicy, including:
-
-* [Calico](/docs/tasks/configure-pod-container/calico-network-policy/)
-* [Cilium](/docs/tasks/administer-cluster/cilium-network-policy/)
-* [Kube-router](/docs/tasks/administer-cluster/kube-router-network-policy/)
-* [Romana](/docs/tasks/configure-pod-container/romana-network-policy/)
-* [Weave Net](/docs/tasks/administer-cluster/weave-network-policy/)
-
-**Note**: The above list is sorted alphabetically by product name, not by recommendation or preference. This example is valid for a Kubernetes cluster using any of these providers.
-{{% /capture %}}
-
 {{% capture prerequisites %}}
 
 {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
 
+Make sure you've configured a network provider with network policy support. There are a number of network providers that support NetworkPolicy, including:
+
+* [Calico](/docs/tasks/administer-cluster/network-policy-provider/calico-network-policy/)
+* [Cilium](/docs/tasks/administer-cluster/network-policy-provider/cilium-network-policy/)
+* [Kube-router](/docs/tasks/administer-cluster/network-policy-provider/kube-router-network-policy/)
+* [Romana](/docs/tasks/administer-cluster/network-policy-provider/romana-network-policy/)
+* [Weave Net](/docs/tasks/administer-cluster/network-policy-provider/weave-network-policy/)
+
+**Note**: The above list is sorted alphabetically by product name, not by recommendation or preference. This example is valid for a Kubernetes cluster using any of these providers.
 {{% /capture %}}
 
 {{% capture steps %}}

content/en/docs/tasks/administer-cluster/dns-horizontal-autoscaling.md

@@ -18,12 +18,6 @@ Kubernetes cluster.
 
 {{% /capture %}}
 
-{{% capture prerequisites %}}
-
-{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
-
-{{% /capture %}}
-
 {{% capture steps %}}
 
 ## Determining whether DNS horizontal autoscaling is already enabled

content/en/docs/tasks/administer-cluster/encrypt-data.md

@@ -17,16 +17,6 @@ This page shows how to enable and configure encryption of secret data at rest.
 
 * etcd v3 or later is required
 
-* Encryption at rest is alpha in 1.7.0 which means it may change without notice. Users may be required to decrypt their data prior to upgrading to 1.8.0.
-
-{{% /capture %}}
-
-{{< toc >}}
-
-{{% capture prerequisites %}}
-
-{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
-
 {{% /capture %}}
 
 {{% capture steps %}}