* Add pull option for 'docker compose up'.
* Improve dry-mode event parsing, and also parse pull-related events.
* Improve error handling, and add first tests.
* Fix action status documentation.
* Add more tests.
* Always return stderr.
This makes debugging misbehavior a lot easier since you can see
what 'docker compose' actually returned.
* Reformat existing tests.
* Add docker_compose_v2 module.
* Add note on compatibility.
* Parse more events.
Emit warnings (or things we assume are warnings), and report unparsable
messages to the user so they can report them to us.
