Use "docker compose" instead of "docker-compose"

Is your feature request related to a problem? Please describe. Docker compose V2 is baked into the docker binary since April this year, and V1 is deprecated. You invoke V1 via docker-compose and you invoke V2 via docker compose.

At the moment, users can change their config to use docker compose instead of docker-compose (see here). The default value is set in the code here.

We need to do a couple things:

1. Update all mentions of 'docker-compose' in the repo to now say 'docker compose'
2. Add a section in the config doc to explain how to switch back to docker-compose

One thing worth thinking about is: should we have some code that runs on startup which checks if your docker version contains compose V2 and if not, fall back to using docker-compose? I would prefer to instead just have a popup that comes up after they've updated to the latest lazydocker which says if they're still using docker-compose they should update the config to use that, or instead update their docker binary to the latest version.