Add landing page for PdfSmith homepage

[Copilot]

This PR adds a professional landing page that displays when users visit the root URL of the PdfSmith application, addressing the need for a clear introduction to the product and its capabilities.

Changes Made

1. Static File Serving

• Added app.UseStaticFiles() middleware to enable serving static content
• Created wwwroot directory for static assets

2. Landing Page (/wwwroot/index.html)

• Modern, responsive design with gradient background and mobile-first approach
• Product introduction with clear value proposition
• 6 key feature highlights:
  • ⚡ Lightning Fast PDF generation with Chromium engine
  • 🎨 Multiple Template Engines (Razor/Scriban support)
  • 🔐 Secure & Scalable with authentication and rate limiting
  • 📱 Responsive Design support for any device
  • 🌍 Internationalization with multi-language support
  • 🔧 Easy Integration via simple REST API
• Quick start example showing API usage with JSON template
• Clear navigation with call-to-action buttons linking to Swagger documentation
• Interactive elements with hover effects and smooth scrolling

3. Root Endpoint

• Added GET / endpoint that redirects to /index.html
• Maintains clean URL structure while serving the landing page
• Excluded from OpenAPI documentation to keep API docs focused

User Experience Improvements

Before: Visiting the root URL resulted in a 404 or default response
After: Users see an informative, professional landing page that:

• Introduces PdfSmith and its capabilities
• Provides clear next steps (API documentation)
• Demonstrates the API with a practical example
• Works seamlessly across all devices

Preserved Functionality

• All existing API endpoints remain unchanged
• Swagger UI still accessible at /swagger
• Authentication, rate limiting, and other middleware unchanged
• No breaking changes to existing integrations

Testing

• ✅ Root endpoint redirects correctly (302 → /index.html)
• ✅ Landing page serves successfully (200 status)
• ✅ Responsive design works on mobile and desktop
• ✅ All navigation links function properly
• ✅ Existing API functionality preserved
• ✅ Build process remains intact

Fixes #7.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• aka.ms
  • Triggering command: curl -I -sSL --retry 5 --retry-delay 2 --connect-timeout 15 REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to my firewall allow list

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[marcominerva]

Add a Fav icon to the site