Add support for docker-compose.

[saevarom]

An iteration on some Makefile commands I added earlier. I realised that it was too hard to manage the container using only docker, it's much nicer to use docker-compose. This makes it easier to manage the container with volumes to make the database persistent, and for developers to make changes to the editor guide code and test them out on the running container.

I did have to make my own version of the Dockerfile but only because I couldn't override the POETRY_INSTALL_ARGS setting in the Dockerfile.