feat: add interactive reveal button for code overlay and improve UI responsiveness (#261)

- Implemented a button to toggle display of lengthy code snippets with smooth animations
- Added styles for overlay, button, and responsive behavior, including reduced motion support
- Enhanced user experience by hiding scroll indicator when overlay is active
- Updated event handling to manage overlay visibility and animations effectively
- Included media queries for mobile and reduced motion preferences
- Minor code adjustments for better maintainability and visual consistency

Author: jumski