docker compose yml

[csloz]

Maybe would be nice to have an example docker-compose yml in the repo
Mine looks something like -

esp-updater:
image: kstobbe/esp-update-server:latest
container_name: esp-updater
ports:
- 5000:5000
volumes:
- /opt/esp-updater:/esp-update-server/bin

[ edit volume path as appropriate ]