Add WebhookAdmission reference

This is a reference for WebhookAdmission config generated from kubernetes-sigs/reference-docs/genref tool.
More specifically, it is generated using the following command:

```shell
./genref -include apiserver-webhookadmission
```

content/en/docs/reference/_index.md

@@ -73,16 +73,11 @@ operator to use or manage a cluster.
 
 * [kubelet configuration (v1beta1)](/docs/reference/config-api/kubelet-config.v1beta1/)
 * [kube-scheduler configuration (v1beta1)](/docs/reference/config-api/kube-scheduler-config.v1beta1/)
+* [kube-scheduler policy reference (v1)](/docs/reference/config-api/kube-scheduler-policy-config.v1/)
 * [kube-proxy configuration (v1alpha1)](/docs/reference/config-api/kube-proxy-config.v1alpha1/)
 * [`audit.k8s.io/v1` API](/docs/reference/config-api/apiserver-audit.v1/)
-
-## Config APIs
-
 * [Client authentication API (v1beta1)](/docs/reference/config-api/client-authentication.v1beta1/)
-
-## Config APIs
-
-* [kube-scheduler policy reference (v1)](/docs/reference/config-api/kube-scheduler-policy-config.v1/)
+* [WebhookAdmission configuration (v1)](/docs/reference/config-api/apiserver-webhookadmission.v1/)
 
 ## Design Docs
 

content/en/docs/reference/access-authn-authz/extensible-admission-controllers.md

@@ -147,7 +147,7 @@ webhooks:
 {{< /tabs >}}
 
 The scope field specifies if only cluster-scoped resources ("Cluster") or namespace-scoped
-resources ("Namespaced") will match this rule. "*" means that there are no scope restrictions.
+resources ("Namespaced") will match this rule. "&lowast;" means that there are no scope restrictions.
 
 {{< note >}}
 When using `clientConfig.service`, the server cert must be valid for
@@ -225,7 +225,7 @@ plugins:
 {{< /tabs >}}
 
 For more information about `AdmissionConfiguration`, see the
-[AdmissionConfiguration schema](https://github.com/kubernetes/kubernetes/blob/v1.17.0/staging/src/k8s.io/apiserver/pkg/apis/apiserver/v1/types.go#L27).
+[AdmissionConfiguration (v1) reference](/docs/reference/config-api/apiserver-webhookadmission.v1/).
 See the [webhook configuration](#webhook-configuration) section for details about each config field.
 
 * In the kubeConfig file, provide the credentials:

content/en/docs/reference/config-api/apiserver-webhookadmission.v1.md

@@ -0,0 +1,46 @@
+---
+title: WebhookAdmission Configuration (v1)
+content_type: tool-reference
+package: apiserver.config.k8s.io/v1
+auto_generated: true
+---
+Package v1 is the v1 version of the API.
+
+## Resource Types 
+
+
+- [WebhookAdmission](#apiserver-config-k8s-io-v1-WebhookAdmission)
+  
+    
+
+
+## `WebhookAdmission`     {#apiserver-config-k8s-io-v1-WebhookAdmission}
+    
+
+
+
+
+WebhookAdmission provides configuration for the webhook admission controller.
+
+<table class="table">
+<thead><tr><th width="30%">Field</th><th>Description</th></tr></thead>
+<tbody>
+    
+<tr><td><code>apiVersion</code><br/>string</td><td><code>apiserver.config.k8s.io/v1</code></td></tr>
+<tr><td><code>kind</code><br/>string</td><td><code>WebhookAdmission</code></td></tr>
+    
+
+  
+  
+<tr><td><code>kubeConfigFile</code> <B>[Required]</B><br/>
+<code>string</code>
+</td>
+<td>
+   KubeConfigFile is the path to the kubeconfig file.</td>
+</tr>
+    
+  
+</tbody>
+</table>
+    
+