Update scaffold-identity.md (#8499)

* Update scaffold-identity.md

* Update scaffold-identity.md

aspnetcore/security/authentication/scaffold-identity.md

@@ -83,6 +83,10 @@ Optional: Add the login partial (`_LoginPartial`) to the layout file:
 <!--
 Use >=2.1: dotnet new webapp -au Individual -o RPauth
 Use = 2.0: dotnet new razor -au Individual -o RPauth
+
+dotnet new webapp -au Individual -o RPauth
+
+dotnet new razor -au Individual -o RPauth
 cd RPauth
 dotnet add package Microsoft.VisualStudio.Web.CodeGeneration.Design
 dotnet restore
@@ -163,3 +167,9 @@ The following the code sets the [LoginPath](/dotnet/api/microsoft.aspnetcore.aut
 Register an `IEmailSender` implementation, for example:
 
 [!code-csharp[](scaffold-identity/sample/StartupFull.cs?name=snippet4)]
+
+[!code-csharp[](scaffold-identity/sample/StartupFull.cs?name=snippet)]
+
+## Additional resources
+
+* [Changes to authentication code to ASP.NET Core 2.1 and later](xref:migration/20_21#changes-to-authentication-code)