Add local files volume mount support for both relative path and absolute path

[t83714]

Currently, dockerode-compose only supports volume mount when source is a volume name.
e.g.:

services:
  backend:
    image: awesome/backend
    volumes:
      - db-data:/data
volumes:
  db-data:

Local files volume mount is not supported. e.g.:

services:
  backend:
    image: awesome/backend
    volumes:
      # relative path local file volume mount
      - ./my-local-config-file.json:/etc/my-local-config-file.json

or

services:
  backend:
    image: awesome/backend
    volumes:
      # absolute path local file volume mount
      - /my-project/dir1/my-local-config-file.json:/etc/my-local-config-file.json

This PR:

• adds local files volume mount support for both relative path and absolute path
  • this PR: Volume source allowed to be relative path #10 unfortunately doesn't support absolute path
• supports both volumes mount short syntax & long syntax