fix(mnq): add question to faq

Author: RoRoJ

pages/queues/faq.mdx

@@ -21,4 +21,10 @@ We currently implement the API endpoints listed [here](/queues/reference-content
 
 ## How is Scaleway Queues billed?
 
-Billing is based on [queue volume](/queues/concepts/#queue-volume) - the combined size of the messages travelling through queues. For full pricing details, see our [dedicated pricing page](https://www.scaleway.com/en/pricing/).
+Billing is based on [queue volume](/queues/concepts/#queue-volume) - the combined size of the messages travelling through queues. For full pricing details, see our [dedicated pricing page](https://www.scaleway.com/en/pricing/).
+
+## Do Scaleway FIFO queues support the `MessageGroupId` identifier?
+
+No, as stated on our [Supported Actions](/queues/reference-content/queues-support/) page, Scaleway Queues do not currently support `MessageGroupid`.
+
+To ensure strict message ordering, FIFO queues on Scaleway are designed to allow only one message to be in flight at a time per queue. Because of this, there is no concept of message grouping. If you are using a Serverless Function triggered by the queue, the system will only deliver one message at a time, limiting horizontal scaling, as concurrent processing of independent message batches is not possible.