Refactor project structure and enhance Docker configuration

- Updated `.dockerignore` to exclude test and development artifacts, optimizing the Docker image size.
- Refactored `main.py` to delegate execution to `duty_teller.run.main()`, simplifying the entry point.
- Introduced a new `duty_teller` package to encapsulate core functionality, improving modularity and organization.
- Enhanced `pyproject.toml` to define a script for running the application, streamlining the execution process.
- Updated README documentation to reflect changes in project structure and usage instructions.
- Improved Alembic environment configuration to utilize the new package structure for database migrations.

tests/test_config.py

@@ -1,6 +1,6 @@
 """Tests for config.is_admin and config.can_access_miniapp."""
 
-import config
+import duty_teller.config as config
 
 
 def test_is_admin_true_when_in_admin_list(monkeypatch):