Add fly.io config

[janbaykara]

• Staging toml
• Production toml
• Github actions for deployment
• Fly scripts for configuring DB / storage
• Maintenance Fly scripts for regularly restarting the apps and databases
• README for setup

[janbaykara]

Would like to include MinIO in this:

• https://fly.io/docs/app-guides/minio/
• https://github.com/py-pa/django-minio-storage

[janbaykara]

Recent examples we can pull the code from:

• https://github.com/commonknowledge/leftbookclub
• https://github.com/commonknowledge/hotosm-website