Update outdated doc link (#2799)

Addresses [this devcom feedback](https://developercommunity.visualstudio.com/t/Runsettings-documentation-leads-you-down/1353353)

The previous link pointed to an outdated doc link where the "Recommended Version" led to a dead end. 
I have updated the link to point to the same doc in a new location

src/Microsoft.TestPlatform.Utilities/InferRunSettingsHelper.cs

@@ -37,7 +37,7 @@ public class InferRunSettingsHelper
         private const string ResultsDirectoryNodePath = @"/RunSettings/RunConfiguration/ResultsDirectory";
         private const string TargetDeviceNodePath = @"/RunSettings/RunConfiguration/TargetDevice";
         private const string EnvironmentVariablesNodePath = @"/RunSettings/RunConfiguration/EnvironmentVariables";
-        private const string multiTargettingForwardLink = @"http://go.microsoft.com/fwlink/?LinkID=236877&clcid=0x409";
+        private const string multiTargettingForwardLink = @"https://aka.ms/tp/vstest/multitargetingdoc?view=vs-2019";
 
         // To make things compatible for older runsettings
         private const string MsTestTargetDeviceNodePath = @"/RunSettings/MSPhoneTest/TargetDevice";

test/Microsoft.TestPlatform.Utilities.UnitTests/InferRunSettingsHelperTests.cs

@@ -25,6 +25,7 @@ public class InferRunSettingsHelperTests
 		private readonly Framework frameworkNet45 = Framework.FromString(".NETFramework,Version=4.5");
 		private readonly Framework frameworkNet46 = Framework.FromString(".NETFramework,Version=4.6");
 		private readonly Framework frameworkNet47 = Framework.FromString(".NETFramework,Version=4.7");
+		private const string multiTargettingForwardLink = @"https://aka.ms/tp/vstest/multitargetingdoc?view=vs-2019";
 
 		public InferRunSettingsHelperTests()
 		{
@@ -404,7 +405,7 @@ public void FilterCompatibleSourcesShouldIdentifyIncomaptiableSourcesAndConstruc
 			sb.AppendLine(GetSourceIncompatibleMessage("x64net47.exe"));
 			sb.AppendLine(GetSourceIncompatibleMessage("x86net45.dll"));
 
-			var expected = string.Format(CultureInfo.CurrentCulture, OMResources.DisplayChosenSettings, frameworkNet47, Constants.DefaultPlatform, sb.ToString(), @"http://go.microsoft.com/fwlink/?LinkID=236877&clcid=0x409");
+			var expected = string.Format(CultureInfo.CurrentCulture, OMResources.DisplayChosenSettings, frameworkNet47, Constants.DefaultPlatform, sb.ToString(), multiTargettingForwardLink);
 			#endregion
 
 			string warningMessage = string.Empty;
@@ -428,7 +429,7 @@ public void FilterCompatibleSourcesShouldIdentifyCompatibleSources()
 			sb.AppendLine();
 			sb.AppendLine(GetSourceIncompatibleMessage("x64net45.exe"));
 
-			var expected = string.Format(CultureInfo.CurrentCulture, OMResources.DisplayChosenSettings, frameworkNet45, Constants.DefaultPlatform, sb.ToString(), @"http://go.microsoft.com/fwlink/?LinkID=236877&clcid=0x409");
+			var expected = string.Format(CultureInfo.CurrentCulture, OMResources.DisplayChosenSettings, frameworkNet45, Constants.DefaultPlatform, sb.ToString(), multiTargettingForwardLink);
 
 			string warningMessage = string.Empty;
 			var compatibleSources = InferRunSettingsHelper.FilterCompatibleSources(Constants.DefaultPlatform, Constants.DefaultPlatform, frameworkNet45, sourceArchitectures, sourceFrameworks, out warningMessage);