Kubernetes on Azure Stack Hub in GA

We now support Kubernetes cluster deployment on Azure Stack Hub, a [certified Kubernetes](https://www.cncf.io/certification/software-conformance/) Cloud Service Provider. Install Kubernetes using Azure Resource Manager templates generated by ACS Engine on Azure Stack Hub. [See more information about deploying Kubernetes on Azure Stack Hub](https://docs.microsoft.com/en-us/azure-stack/user/azure-stack-kubernetes-aks-engine-overview). * Services