Fix API cross-link (#35966)

Author: guardrex

aspnetcore/fundamentals/openapi/using-openapi-documents.md

@@ -102,7 +102,7 @@ The output shows any issues with the OpenAPI document. For example:
 
 ## Support for injecting `IOpenApiDocumentProvider`
 
-You can inject `Microsoft.AspNetCore.OpenApi.Services.IOpenApiDocumentProvider` into your services through dependency injection to access OpenAPI documents programmatically, even outside HTTP request contexts.
+You can inject <xref:Microsoft.AspNetCore.OpenApi.IOpenApiDocumentProvider> into your services through dependency injection to access OpenAPI documents programmatically, even outside HTTP request contexts.
 
 ```csharp
 public class DocumentService