many changes, tested

[froeb]

Added

• Custom colors for headings, captions, blockquotes, and listings.
• Custom commands \customheading and \customcaption for flexible styling.
• Support for custom background images on title pages and all pages.
• Flexible geometry settings for title page layout.
• Enhanced handling of paragraph and list spacing.
• New variables for header and footer customization: footer-center, footer-left, and footer-right.
• Customizable copyright text through the footer-left variable with a new \copyrighttext macro.

Changed

• Updated README.md to include detailed instructions on using and customizing the template.
• Integrated custom styling options directly into the template for better user experience.
• Enhanced flexibility for setting date values via the date variable.
• Default behavior for footer-right now includes the total page count (\thepage{} / \pageref{LastPage}).

Fixed

• Minor formatting issues and improved compatibility with various LaTeX distributions.
• Corrected handling of page numbers in the footer to prevent duplication.