docker-compose.yml: use relative command path
docker-compose.yml: use relative command path

No need to include the `/smr` path prefix in commands, since that
is the working directory for the smr image.

smrealms/smr,smrealms/smr,hemberger/smr,hemberger/smr,hemberger/smr,smrealms/smr,hemberger/smr