docker-compose instead docker compose

[XDavidT]

I saw documents are still showing docker-compose commands, while docker not supported anymore with this.
You should update it into docker compose

[cgrinds]

Thanks @XDavidT! Originally the documentation only used docker compose. We reverted to docker-compose because many of our customers had not upgraded to a recent version of Docker (or their package manager hadn't) and it only caused confusion.

We should revisit or make it clearer in the documentation that you should try one or other depending on your docker version. Thanks!