Pytypos

Features
- `pytypos.Pytypos()` now uses keyword arguments only

Misc/Internal
- Refactor to `blue` coding style

Misc/Internal
- Refactor to comply with `pylint`, `isort` and `mypy` checks
- Minor improvements

Features
- Obtain available dictionary languages with `pytypos.available_languages()`

Improvements
- Use consistent path separators where possible
- Use more generic typing

Features
- `Pytypos` object now takes `exclude_file_list`, `exclude_word_list` and `exclude_word_file` arguments

Improvements
- Don't return typo `dict` with `find_typos()`

- First release