Merge pull request #111524 from lgayhardt/appinsightstelecorr0420

 App Insights Correlation broken link fix

Author: PRMerger6

articles/azure-monitor/app/correlation.md

@@ -310,7 +310,7 @@ Over time, .NET has defined several ways to correlate telemetry and diagnostics
 
 But those methods didn't enable automatic distributed tracing support. `DiagnosticSource` supports automatic cross-machine correlation. .NET libraries support `DiagnosticSource` and allow automatic cross-machine propagation of the correlation context via the transport, such as HTTP.
 
-The [Activity User Guide](https://github.com/dotnet/corefx/blob/master/src/System.Diagnostics.DiagnosticSource/src/ActivityUserGuide.md) in `DiagnosticSource` explains the basics of tracking activities.
+The [Activity User Guide](https://github.com/dotnet/runtime/blob/master/src/libraries/System.Diagnostics.DiagnosticSource/src/ActivityUserGuide.md) in `DiagnosticSource` explains the basics of tracking activities.
 
 ASP.NET Core 2.0 supports extraction of HTTP headers and starting new activities.