Complete Docker compose setup for development

[mihow]

• [x] Rename local.yml o docker-compose.yml to make it the default compose config file
• [x] Add MiniIO to compose (see #379)
• [x] Rewrite README with real instructions for development and usage.
• [x] Ensure fresh database make a useable app (Use fixtures, generators, seeders, etc. where necessary)
• [x] Add .env config for UI with API url
• [x] Add back GitHub CI job for backend tests
• [x] Update License (GPLv3)

Moving to follow up tasks:

• Fix type warnings for OpenAPI docs generator
• Add some diagrams to README (model schemas and common workflows)
• Add some images to README
• Add container with prebuilt frontend (so don't need React)
• Add frontend live container to compose?
• Add ML to compose with prebuilt container example #503

See https://docs.google.com/spreadsheets/d/1BytqZZ49ub1cqtQ9xbytAIryc90EZ1OXiUCWHdrBvgs/edit?gid=0#gid=0

[mihow]

Closed by #502

[mihow]

@mihow make tickets for these subtasks:

Fix type warnings for OpenAPI docs generator Add some diagrams to README (model schemas and common workflows) Add some images to README Add container with prebuilt frontend (so don't need React) Add frontend live container to compose?