v4.5.0

• Added language support for Persian (fa)
• Added language support for Bulgarian (bg)
• Corrected several misspelled book names in the Spanish (es) language file
• Fixed several self-cancelling bugs in the 'search reference' unit tests
• Added schema for the search engines data file
• Revised other data file schemas to improve precision, reduce redundancy, and improve overall consistency
• Upgraded coverage and flake8 packages
• Added additional code comments to improve code quality
• Restructured conditional logic in HTML parsers to reduce redundancy and improve readability