Merge pull request #178286 from mrbullwinkle/mrb_11_2_2021_updates_001

[Cognitive Services] Q&A updates remove outdated reference

Author: tfosmark

articles/cognitive-services/QnAMaker/Concepts/data-sources-and-content.md

@@ -64,7 +64,7 @@ If you are unsure how to represent your QnA pair in the `.tsv` file:
 You can also create a knowledge base based on unstructured content imported via a file. Currently this functionality is available only via document upload for documents that are in any of the supported file formats.
 
 > [!IMPORTANT]
-> The support for unstructured content via file upload is available only in Custom question answering (preview release)
+> The support for unstructured content via file upload is available only in [question answering](../../language-service/question-answering/overview.md).
 
 ## Content types of documents you can add to a knowledge base
 Content types include many standard structured documents such as PDF, DOC, and TXT.