Add AspNetCore example for log correlation (#1267)

* Add AspNetCore example for log correlation

* remove space

* link to non host console

docs/logs/correlation/README.md

@@ -3,7 +3,9 @@
 Starting from `Microsoft.Extensions.Logging` version `5.0`, logs can be
 correlated with distributed tracing by enriching each log entry with the
 information from the enclosing `Activity`. This can be achieved by enabling the
-`ActivityTrackingOptions`:
+`ActivityTrackingOptions`. In a [non-host console
+app](https://docs.microsoft.com/aspnet/core/fundamentals/logging#non-host-console-app),
+it can be achieved as shown below.
 
 ```csharp
 using var loggerFactory = LoggerFactory.Create(builder =>
@@ -14,11 +16,28 @@ using var loggerFactory = LoggerFactory.Create(builder =>
 });
 ```
 
+Please refer to the example [here](./Program.cs).
+
+In an ASP.NET Core app, the above can be achieved by modifying the host
+building, as shown below.
+
+```csharp
+public static IHostBuilder CreateHostBuilder(string[] args) =>
+    Host.CreateDefaultBuilder(args)
+        .ConfigureLogging(loggingBuilder =>
+            loggingBuilder.Configure(options =>
+                options.ActivityTrackingOptions =
+                    ActivityTrackingOptions.TraceId
+                    | ActivityTrackingOptions.SpanId))
+        .ConfigureWebHostDefaults(webBuilder =>
+        {
+            webBuilder.UseStartup<Startup>();
+        });
+```
+
 `Microsoft.Extensions.Logging.ActivityTrackingOptions` supports `TraceId`,
 `SpanId`, `ParentId`, `TraceFlags` and `TraceState`.
 
-Please refer to the example [here](./Program.cs).
-
 ## References
 
 * [ILogger](https://docs.microsoft.com/dotnet/api/microsoft.extensions.logging.ilogger)