Support of "Motion activity zone"
**Is your feature request related to a problem? Please describe:**
Just discover that official HomeKit camera can use a motion detection based on activity zone (see picture above).
I understand that this plugin can trigger a notification on motion detection thanks to https://sunoo.github.io/homebridge-camera-ffmpeg/automation/motion.html but I am unable to find here if the plugin allow to have this activity zone feature, can someone tell me if it's possible?

Thank you!

![image](https://user-images.githubusercontent.com/11562279/161596417-035d0053-6ed9-4526-86f4-9e8d3fb2ff75.png)


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