Add print stylesheet

[dannon]

Description

Add print-specific styles so articles and documentation print cleanly.

Tasks

1. Add @media print styles to hide navigation, sidebar, footer
2. Ensure content is readable in print (appropriate fonts, sizes)
3. Handle images appropriately (don't break across pages)
4. Add URL display for links when printing
5. Test with browser print preview

Key considerations

• Hide interactive elements (search, mobile menu toggle)
• Ensure code blocks print with syntax visible
• Handle tables that might be too wide