This small docker container will download the latest raspios.
After downloading the zip, it will be extracted, mounted and patched with any
public keys that are found in the keys directory.
Simply place any public ssh keys you want to be added to the image to the
keys directory, i.e., by running cp ~/.ssh/*.pub keys/, then run
docker-compose up in the project root. Everything else will happen
automatically. Also, if any keys are supplied, ssh password authentication is
being disabled.
If there is a file named wpa_supplicant.conf in the project root, it will
also be patched right into the image.
After the job has completed, you will be left with the patched raspios image
file which is ready to be written to an SD card by using dd or whatever.