Merge pull request #192302 from AaronMaxwell/aaronmax-update-dotnet-req

[AppInsights][AaronMax] updating dotnet prereq

Author: PRMerger17

articles/azure-monitor/app/migrate-from-instrumentation-keys-to-connection-strings.md

@@ -97,7 +97,7 @@ Connection strings provide a single configuration setting and eliminate the need
 
 ## Supported SDK Versions
 
-- .NET and .NET Core v2.12.0+
+- .NET and .NET Core [LTS](https://dotnet.microsoft.com/download/visual-studio-sdks)
 - Java v2.5.1 and Java 3.0+
 - JavaScript v2.3.0+
 - NodeJS v1.5.0+