Migrate docker compose file names to Compose V2

[omarlopesino]

According to new compose versions, the files must start with compose, instead of starting with docker-compose as before: https://docs.docker.com/compose/compose-application-model/

The default path for a Compose file is compose.yaml (preferred) or compose.yml that is placed in the working directory. Compose also supports docker-compose.yaml and docker-compose.yml for backwards compatibility of earlier versions. If both files exist, Compose prefers the canonical compose.yaml.

We should change the file names to meet the new standard.

Pull requests related:

Metadrop/drupal-boilerplate-assistant#1
#140

[omarlopesino]

@rsanzante may you review the pull requests?

[rsanzante]

Changes requested in the assistant PR, see Metadrop/drupal-boilerplate-assistant#1 (review)

[omarlopesino]

All changes requested in the feedback have been done and both the assistant and the boilerplate are ready to be merged.