Shelly Integration: Add entity for Firmware Update Available

The old Shelly integration in the HACS used to expose a switch entity for each Shelly device that flipped to “on” if there was a firmware update available for that device. This helped me make sure that all of my devices stayed up-to-date.

I’d love to see this added to the newer official integration.

Thanks!

https://github.com/home-assistant/core/pull/40429 You have to wait for HA 1.0.