Add first version of Dockerfile and docker-compose

Some optimizations are still possible:

copying dist folder to a smaller Docker image without build tools aka multi-stage build => end image is smaller
using the output of this Dockerfile as image for the registry => more consistent and transparent
source conf folder including routes and translations => more simplicity, we can mount the whole conf folder in docker-compose
dockerignore file => less files in end or intermediary images
reviewing the README regarding prebuilt docker image, conf folder should also be mounted there I think to enable editing

nymanjens / quizmaster