Improve Docker setup for development env

[jigarius]

Requirements

Tried using a quick Ddev setup, but it made life difficult to a great extent. Here's what would help:

• Create a docker-compose.yml
  • Use the official Drupal docker image
  • Use the official MariaDB docker image
• Expose files/directories using volumes
  • composer.json
  • sites.php
  • drush directory
• Create working multi-site setup
  • All sites should have drush aliases.
  • All sites should have a separate database.
• Optionally, all sites should be accessible using the browser?
  • This will probably need modification of the /hosts file.
• Mount drall at /opt/drall
  • It should be possible to run drall from anywhere inside the container.