todo list before v2.0.0-rc

[antondlr]

• [x] provide default .env file if none provided
• [x] clean up logging from the container
• [x] better error handling on startup (i.e., APIs unavailable)
• [ ] prepare lighthouse-book for new version
• [x] update README
• [x] update workflows
• [x] 3rd party testing / look-over: is the container in its current form user-friendly and stable enough?
• [x] add a docker-compose file
• [x] bump version in package.json
• [x] assign a license in backend/package.json