Mkdocs-exporter

**Changelog**

- `mkdocs/exporter/pdf`:
- Fixed wrong condition controlling cover pages visibility

**Full changelog**: https://github.com/adrienbrignon/mkdocs-exporter/compare/v1.2.1...v1.2.2

**Changelog**

- `mkdocs/exporter/pdf`:
- Resolved an error when generating PDF files

**Full changelog**: https://github.com/adrienbrignon/mkdocs-exporter/compare/v1.2.0...v1.2.1

**Changelog**

- `docs`:
- Slightly improved the documentation
- `mkdocs/exporter/pdf`:
- Cover pages can now be defined per page
- Cover pages can now be hidden completely or individually
- Miscellaneous enhancements and fixes

**Full changelog**: https://github.com/adrienbrignon/mkdocs-exporter/compare/v1.1.0...v1.2.0

**Changelog**

- `mkdocs/exporter/pdf`:
- **Explicit mode**: define explicitly all pages that should be rendered as PDF
- **Misc. fixes**: URLs resolution, cover pages, compatiblity with theme...

**Changelog**

- `mkdocs/exporter/pdf`: Respect the `enabled` configuration value

**Changelog**

- Improved compatibility with other dependencies
- Now linting the source code with `flake8`