New minor version: 2.2

Added

• new unit tests, a code formatter (black) and a linter (pylint) to improve code quality
• new boolean parameter table_line_separators for HTMLMixin.write_html & underlying HTML2FPDF constructor

Changed

• the documentation URL is now simply https://pyfpdf.github.io/fpdf2/

Removed

• dropped support for external font definitions in .font Python files, that relied on a call to exec

Deprecated

• the type parameter of FPDF.image method
• the infile parameter of Template constructor
• the dest parameter of Template.render method