A new support document confirms the long-standing rumor that Apple TVs (third-generation or later) will allow users to control HomeKit devices using Siri even when they’re away from home. Devices running iOS 8.1 or later will be able to control HomeKit devices locally after downloading an app for each family of devices and entering a unique HomeKit code. After setup, Siri will be able to control the HomeKit products inside the house, but the…