Licensecheck

- Command-line options take precedent over config options as expected

- Add config file functionality per https://github.com/FHPythonUtils/LicenseCheck/issues/11
- Parsed in the following order: `pyproject.toml`, `setup.cfg`, `licensecheck.toml`, `licensecheck.json`, `licensecheck.ini`, `~/licensecheck.toml`, `~/licensecheck.json`, `~/licensecheck.ini`
- Note that the config takes precedent over command-line options
- Add optional path to requirements.txt as outlined in https://github.com/FHPythonUtils/LicenseCheck/issues/9#issuecomment-898878228
- Eg. `licensecheck --using requirements:c:/path/to/reqs.txt;path/to/other/reqs.txt`

- Add `--ignore-packages`, `--fail-packages`,`--ignore-licenses`, `--fail-licenses`, per https://github.com/FHPythonUtils/LicenseCheck/issues/7
- Fix spelling
- Added a couple examples to the readme
- Added pylintrc to pyproject.toml

- Added ability to use requirements.txt per https://github.com/FHPythonUtils/LicenseCheck/issues/6
- Code clean-up + refactoring
- Fix spelling
- packagecompat.py → types.py as this module holds types + typing info

- reformat
- improve docstrings

- Add PSFL to matrix.