Add docs for fifo sqs

Signed-off-by: Thomas Sands <[email protected]>

docs/services/awssqs.md

@@ -1,8 +1,8 @@
-# AWS SQS 
+# AWS SQS
 
 ## Parameters
 
-This notification service is capable of sending simple messages to AWS SQS queue. 
+This notification service is capable of sending simple messages to AWS SQS queue.
 
 * `queue` - name of the queue you are intending to send messages to. Can be overridden with target destination annotation.
 * `region` - region of the sqs queue can be provided via env variable AWS_DEFAULT_REGION
@@ -104,3 +104,16 @@ data:
     - oncePer: obj.metadata.annotations["generation"]
 
 ```
+
+## FIFO SQS Queues
+
+FIFO queues require a [MessageGroupId](https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_SendMessage.html#SQS-SendMessage-request-MessageGroupId) to be sent along with every message, every message with a matching MessageGroupId will be processed one by one in order.
+
+To send to a FIFO SQS Queue you must include a `messageGroupId` in the template such as in the example below:
+
+```yaml
+template.deployment-ready: |
+  message: |
+    Deployment {{.obj.metadata.name}} is ready!
+  messageGroupId: {{.obj.metadata.name}}-deployment
+```