List of short-term improvements

[shiftedreality]

The list of improvements, requested by Community Engineering:

• Merge the documentation (including .magento.env.yaml universal confgiruration) updates: MCLOUD-5667: Add Universal Configuration documentation devdocs#6975 (@shiftedreality, @meker12)
• Include a bare minimum of different docker-compose.yml files for different platforms and use-cases
• Include the minimal installation instruction into README.md without PHP and Composer installed locally
• Add support to core development and documentation

[meker12]

I think most of these have been addressed in the Docker documentation now available on developer.adobe.com