How to update homebridge-raspbian OS itself?  I have 1.0.9 and want to move to 1.0.15
A few months ago I installed homebridge-raspbian-image 1.0.9
I notice that it is up to 1.0.15 now, and I'd like to upgrade.
I know how to upgrade homebridge, homebridge-ui, the plugins, and node itself and keep those up to date
How do I upgrade the OS itself?  Or do I have to reflash my SD card (and if so, how do I keep my config?)



**Environment:**

* **Homebridge Raspberry Pi Image Version**: 1.0.9
* **Node.js Version**: 14.15.1
* **NPM Version**: 6.14.8
* **Homebridge Version**: 1.2.3
* **Homebridge Config UI X Plugin Version**: 4.3.4
