Documentation: Missing examples for ASP.NET Core integration

[hokagedami]

Documentation Issue

The current README doesn't have examples for ASP.NET Core integration, which is probably the most common use case.

What's Missing

• How to register in Program.cs with dependency injection
• Configuration with appsettings.json
• Integration with ASP.NET Core's built-in logging
• Performance considerations for web applications

Proposed Sections

Basic Integration

// Program.cs
builder.Services.AddLogging(loggingBuilder =>
    loggingBuilder.AddSerilog(new LoggerConfiguration()
        .Enrich.WithCallStack()
        .WriteTo.Console()
        .CreateLogger()));

Configuration

{
  "Serilog": {
    "Using": ["Serilog.Enrichers.CallStack"],
    "Enrich": ["WithCallStack"]
  }
}

Controller Usage

Examples showing how the enricher works with controller actions, middleware, and exception handling.

This would help adoption significantly. I can submit a PR with these examples if needed!