add question about gRPC

Author: duongau

articles/frontdoor/front-door-faq.yml

@@ -6,7 +6,7 @@ metadata:
   ms.author: duau
   ms.service: frontdoor
   ms.topic: faq
-  ms.date: 11/08/2023
+  ms.date: 06/17/2024
 title: Frequently asked questions for Azure Front Door
 summary: |
   This article answers common questions about Azure Front Door features and functionality. If you don't see the answer to your question, you can contact us through the following channels (in escalating order):
@@ -146,6 +146,11 @@ sections:
           > Custom TLS/SSL certificate updates might take longer, from several minutes up to an hour, to be deployed globally.
           
           Updates to routes or origin groups/backend pools are seamless and don't cause any downtime (assuming the new configuration is correct). Certificate updates are also done atomically, so there's no risk of outage.
+
+      - question: |
+          Does Azure Front Door support gRPC?
+        answer:  |
+          No. Currently, Azure Front Door only supports HTTP/1.1 from the edge to the origin. For gRPC to work, HTTP/2 is required.
           
   - name: Configuration
     questions: