Fix markdown links

Author: AArnott

README.md

@@ -1,7 +1,7 @@
 Microsoft.VisualStudio.Validation
 =================================
 
-[![NuGet package](https://img.shields.io/nuget/v/Microsoft.VisualStudio.Validation.svg)](https://nuget.org/packages/Microsoft.VisualStudio.Validation)
+[![NuGet package](https://img.shields.io/nuget/v/Microsoft.VisualStudio.Validation.svg)](https://www.nuget.org/packages/Microsoft.VisualStudio.Validation)
 [![Build Status](https://dev.azure.com/azure-public/vside/_apis/build/status/vs-validation?branchName=main)](https://dev.azure.com/azure-public/vside/_build/latest?definitionId=11&branchName=main)
 [![codecov](https://codecov.io/gh/Microsoft/vs-validation/branch/main/graph/badge.svg)](https://codecov.io/gh/Microsoft/vs-validation)
 
@@ -33,4 +33,4 @@ Warning signs that should not throw exceptions via the `Report` class.
 Report.IfNot(condition, "some error");
 ```
 
-[1]: http://nuget.org/packages/Microsoft.VisualStudio.Validation "Microsoft.VisualStudio.Validation NuGet package"
+[1]: http://www.nuget.org/packages/Microsoft.VisualStudio.Validation "Microsoft.VisualStudio.Validation NuGet package"