the default docker compose file should be minimal and easy to read as docker-compose.yml
other docker-compose variants for typical setup should be named as:
docker-compose.<variant>.yml
this way one could use e.g. `docker compose -f docker-compose.traefik.yml up` to
start the variant for traefik. (mind keeping the file extension)
and fixed a typo the README.md
user defined data should not be mixed with static application data in
one directory.
therefore we need to move some files like db and userconfig to separate
directories, which can then be declared as docker volumes.
