Leaf-focus

[full change log](https://github.com/anotherbyte-net/leaf-focus/compare/v0.4.0...v0.4.1)

- Dependency updates
- Improved OCR tests
- Improved tests when running in CI

- Implement wrapper for [keras-ocr](https://github.com/faustomorales/keras-ocr)
- Implement wrapper for [xpdf tools](https://www.xpdfreader.com/about.html)
- Implement initial cli using Python's argparse
- Add docs and doc generation using [pdoc3](https://github.com/pdoc3/pdoc)