Fastapi-injector

- Add missing README to package metadata

- Add `py.typed` marker
- Drop support for python3.6
- Switch from setup.py and requirements.txt to poetry/pyproject.toml

- Added `get_injector_instance` to `__all__`

**Full Changelog**: https://github.com/matyasrichter/fastapi-injector/commits/0.1.1

Initial release