Add API documentation with Swagger/OpenAPI

[coder-contrib-bot]

Description

Currently, there's no easy way for developers to understand the available API endpoints and how to use them. Adding Swagger/OpenAPI documentation would improve the developer experience and provide interactive API documentation.

Implementation Details

1. Install and configure drf-spectacular or drf-yasg in the Django backend
2. Add OpenAPI schema generation to the Django settings
3. Add appropriate docstrings and annotations to API views and serializers
4. Configure a URL endpoint to serve the Swagger UI
5. Generate static documentation for offline use
6. Update the README with links to the API documentation

Benefits

• Interactive documentation for API endpoints
• Improved developer onboarding experience
• Self-documenting API that stays in sync with the code
• Testing interface for API endpoints
• Better collaboration between frontend and backend teams

Testing

• Verify all endpoints are properly documented
• Test the Swagger UI functionality
• Ensure authentication is properly configured in the documentation
• Validate the OpenAPI schema against the specification