Summary:
Make it possible to specify multiple config files.
Parsing CLI is not a special case anymore, just uses the same config inheritance method.
Test Plan:
Test that this iterpolates in the right order via unit tests
Sample usage, loads the internal config, which references bytelatent/configs/entropy_model.yaml. The precendence order is:
- Default pydantic args
- Included configs, eg `config`
- CLI args
```
python -m bytelatent.print_config config=internal/configs/entropy_model.yaml eval=null
```