📣 borb release notes

• Added support for (some) password-protected PDF documents
• Added test to check whether all imports are fully qualified
• Added test to check whether all imports are in the requirements
• Added test to check whether all imports are single line
• Added CodeBlockWithSyntaxHighlighting LayoutElement
• Ran black
• Ran optimize imports
• Removed dependency on lxml, which is only needed for HTMLToPDF