Correct description of registering APIService

APIService doesn't have `path` field and cannot call a service at
specified subpath. This might be a copy-paste error from service in CRD
webhook.

Author: tnqn

content/en/docs/tasks/access-kubernetes-api/configure-aggregation-layer.md

@@ -251,15 +251,14 @@ The name of an APIService object must be a valid
 
 #### Contacting the extension apiserver
 
-Once the Kubernetes apiserver has determined a request should be sent to a extension apiserver,
+Once the Kubernetes apiserver has determined a request should be sent to an extension apiserver,
 it needs to know how to contact it.
 
-The `service` stanza is a reference to the service for a extension apiserver.
+The `service` stanza is a reference to the service for an extension apiserver.
 The service namespace and name are required. The port is optional and defaults to 443.
-The path is optional and defaults to "/".
 
-Here is an example of an extension apiserver that is configured to be called on port "1234"
-at the subpath "/my-path", and to verify the TLS connection against the ServerName
+Here is an example of an extension apiserver that is configured to be called on port "1234",
+and to verify the TLS connection against the ServerName
 `my-service-name.my-service-namespace.svc` using a custom CA bundle.
 
 ```yaml