Rename all docker-compose.y[a]ml to compose.yaml #6874

The compose spec specifies (https://docs.docker.com/compose/compose-file/03-compose-file/):

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.

All mentions of docker-compose.yml and docker-compose.yaml should be changed to compose.yaml.