Remove exposed ports from dev docker compose config

[encounter]

This removes unnecessarily exposed ports from the dev docker-compose.yml. Since the application communicates with these services using the internal docker network, they aren't necessary to be exposed on the host. This avoids port conflicts with frequently-used ports. Additionally, this makes the nginx service bind to port 8080, which matches the port you'd use to access the site if using regular yarn dev.

For compatibility with non-Docker container engines, explicitly specifies docker.io/library/ prefix for container image refs.

[mkst]

Hmm I'm not super keen on this change as I find it's handy to be able to directly access the processes (without going through nginx), and sticking nginx on 8080 means you can't just connect to http://localhost

[mkst]

.. but I guess commenting them out (rather than removing entirely) would be a happy medium?

Could you update the DOCKER.md to reflect the nginx port change