Update spec.md fix render typo on DeliverySpec
The <numberOfRetries> field wasn't being rendered in the duck.DeliverySpec
@@ -223,7 +223,7 @@ retrieved from ref.
| deadLetterSink | Destination | DeadLetterSink is the sink receiving event that could not be sent to a destination. | |
| retry | String | Retry is the minimum number of retries the sender should attempt when sending an event before moving it to the dead letter sink. | |
| backoffPolicy | BackoffPolicy | BackoffPolicy is the retry backoff policy (linear, exponential). | |
-| backoffDelay | String | For linear policy, backoff delay is backoffDelay\*<numberOfRetries>. For exponential policy, backoff delay is backoffDelay\*2^<numberOfRetries>. | |
+| backoffDelay | String | For linear policy, backoff delay is backoffDelay\*\<numberOfRetries>. For exponential policy, backoff delay is backoffDelay\*2^\<numberOfRetries>. | |
### duck.SubscriberSpec
