Link ConfigureServices text to app startup content (dotnet#6480)

aspnetcore/tutorials/razor-pages/model.md

@@ -33,7 +33,7 @@ Add a connection string to the *appsettings.json* file.
 <a name="reg"></a>
 ###  Register the database context
 
-Register the database context with the [dependency injection](xref:fundamentals/dependency-injection) container in the *Startup.cs* file.
+Register the database context with the [dependency injection](xref:fundamentals/dependency-injection) container in the [ConfigureServices method of the Startup class](xref:fundamentals/startup#the-startup-class) (*Startup.cs*):
 
 [!code-csharp[](../../tutorials/razor-pages/razor-pages-start/sample/RazorPagesMovie/Startup.cs?name=snippet_ConfigureServices&highlight=3-5,7-9)]