Minor documentation improvement (#35930)

Author: geofvyie

README.md

@@ -1,6 +1,6 @@
 # ASP.NET Core Docs
 
-This repository contains the [ASP.NET Core documentation](https://learn.microsoft.com/aspnet/core/introduction-to-aspnet-core). See the [Contributing Guide](CONTRIBUTING.md) and the [issues list](https://github.com/dotnet/AspNetCore.Docs/issues) if you would like to help.
+This repository contains the official [ASP.NET Core documentation](https://learn.microsoft.com/aspnet/core/introduction-to-aspnet-core). See the [Contributing Guide](CONTRIBUTING.md) and the [issues list](https://github.com/dotnet/AspNetCore.Docs/issues) if you would like to help.
 
 The [`dotnet/AspNetDocs` GitHub repository](https://github.com/dotnet/AspNetDocs)contains the ASP.NET 4.x documentation.