update sample-controller README

remind that CustomResourceSubresources is beta in v1.11 and enabled by default

Kubernetes-commit: ac741a8412d3c73ba39224f2f2e849f9976acc5a

README.md

@@ -105,9 +105,8 @@ $ kubectl create -f artifacts/examples/crd-validation.yaml
 
 ## Subresources
 
-Custom Resources support `/status` and `/scale` subresources as an
-[alpha feature](https://kubernetes.io/docs/tasks/access-kubernetes-api/extend-api-custom-resource-definitions/#subresources) in v1.10.
-Enable this feature using the `CustomResourceSubresources` feature gate on the [kube-apiserver](https://kubernetes.io/docs/admin/kube-apiserver):
+Custom Resources support `/status` and `/scale` subresources as a [beta feature](https://kubernetes.io/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/#subresources) in v1.11 and is enabled by default.
+This feature is [alpha](https://v1-10.docs.kubernetes.io/docs/tasks/access-kubernetes-api/extend-api-custom-resource-definitions/#subresources) in v1.10 and to enable it you need to set the `CustomResourceSubresources` feature gate on the [kube-apiserver](https://kubernetes.io/docs/admin/kube-apiserver):
 
 ```sh
 --feature-gates=CustomResourceSubresources=true