Add comprehensive ASP.NET Core integration examples

[hokagedami]

Overview

This PR addresses #14 by adding comprehensive ASP.NET Core integration documentation and examples.

Changes

• ✅ Program.cs Configuration: Complete setup example with Serilog configuration
• ✅ appsettings.json: JSON-based configuration with proper enricher setup
• ✅ Controller Examples: Realistic controller implementation with error handling
• ✅ Service Layer: Shows call stack tracing through service layers
• ✅ Expected Output: Sample log output showing call stack traces

Key Features Demonstrated

• Request logging middleware integration
• Exception handling with call stack context
• Namespace filtering for cleaner output
• Performance considerations for web apps
• Both code and configuration-based setup

Testing

• ✅ Verified examples compile against latest Serilog versions
• ✅ Tested configuration examples in sample ASP.NET Core app
• ✅ Confirmed output format matches documentation

Impact

This should significantly improve adoption for ASP.NET Core developers who represent the majority of potential users.

Notes

• Examples use minimal APIs and modern ASP.NET Core patterns
• Includes both programmatic and configuration-based setup
• Shows realistic error handling scenarios

Ready for review! Happy to adjust based on feedback.