Add container files

[IceflowRE]

There was/is no documentation on how to run the asset library. I hope that the container files will add more to this and provide an easy way to spin up the asset-library.

Thanks to @Piralein for helping me!

[IceflowRE]

Also moved the docker-compose.yml to docker-compose.example.yml and adjusted the readme to create the docker compose file yourself. This makes it easier to pull the repo later on, if you changed the docker compose file.