Remove initializers feature gate (#14602)

* Remove initializers feature gate

Initializers are removed in 1.14
kubernetes/kubernetes#72972

* Update feature-gates.md

content/en/docs/concepts/extend-kubernetes/extend-cluster.md

@@ -156,7 +156,6 @@ After a request is authorized, if it is a write operation, it also goes through
 
 *   The [Image Policy webhook](/docs/reference/access-authn-authz/admission-controllers/#imagepolicywebhook) restricts what images can be run in containers.
 *   To make arbitrary admission control decisions, a general [Admission webhook](/docs/reference/access-authn-authz/extensible-admission-controllers/#admission-webhooks) can be used. Admission Webhooks can reject creations or updates.
-*   [Initializers](/docs/reference/access-authn-authz/extensible-admission-controllers/#initializers) are controllers that can modify objects before they are created. Initializers can modify initial object creations but cannot affect updates to objects. Initializers can also reject objects.
 
 ## Infrastructure Extensions
 
@@ -210,7 +209,3 @@ the nodes chosen for a pod.
   * [List of Operators](https://github.com/operator-framework/awesome-operators)
 
 {{% /capture %}}
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-
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-

content/en/docs/concepts/workloads/pods/podpreset.md

@@ -74,7 +74,7 @@ In order to use Pod Presets in your cluster you must ensure the following:
 1.  You have enabled the admission controller `PodPreset`. One way to doing this
     is to include `PodPreset` in the `--enable-admission-plugins` option value specified
     for the API server. In minikube add this flag
-    `--extra-config=apiserver.enable-admission-plugins=Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota,PodPreset`
+    `--extra-config=apiserver.enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota,PodPreset`
     while starting the cluster.
 1.  You have defined your Pod Presets by creating `PodPreset` objects in the
     namespace you will use.