Ffmpeg-progress-yield

* Add py.typed.

* Move API docs to existing section.

* Link to API docs.

* Add API docs.

* Add export.

* Bump requirements to python 3.8 or higher.

* Document methods.

* Remove unused import.

* Docs: add WyattBlue as a contributor.

* Docs: add slhck as a contributor.

* Unhide to_ms.

* Add type hints + simplify.

* Add python CI badge.

* Fix quit tests.

* Add all-contributors.

* Add pytest to dev requirements.

* Add github workflows.

* Formatting.

* Fix a few type and formatting errors.

* Add stderr callback method.

* Update README.

* Add graceful quit method.

* Add a GIF in the readme.

* Add a quit method, fixes 4.

* Update python requirements.

* Add a usage option.