Ability to incrementally add capacity to Azure Stack

[Azure Stack operators](https://docs.microsoft.com/en-us/azure/azure-stack/azure-stack-key-features) can now add a node to an existing Azure Stack scale unit within the supported scale unit limits. This enables Azure Stack operators to increase the capacity of a single Azure Stack, and specifics should be discussed with [hardware partners](https://azure.microsoft.com/en-us/overview/azure-stack/integrated-systems/). [Get more information](https://docs.microsoft.com/en-us/azure/azure-stack/azure-stack-key-features) about being an Azure Stack operator and hardware partners with [Azure Stack integrated systems](https://azure.microsoft.com/en-us/overview/azure-stack/integrated-systems/). * Azure Stack * Features * [ Azure Stack](https://azure.microsoft.com/en-gb/overview/azure-stack/)