Test makefile and README.md are still using docker compose v1

[GorgiAstro]

It is now recommended to use docker compose v2 syntax, notably the command docker-compose becomes docker compose. I am not a docker expert though so I am not sure whether further changes are required.

Ref: https://docs.docker.com/compose/releases/migrate/#what-are-the-differences-between-compose-v1-and-compose-v2

[jonhealy1]

We should definitely update this.