Docs: show how to retrieve EventHub connection string as template output (#1250)

Author: Copilot

docs/content/api-overview/resources/event-hub.md

@@ -35,8 +35,8 @@ The Event Hub builder creates event hub namespaces, event hubs, consumer groups
 #### Configuration Members
 | Member | Purpose |
 |-|-|
-| DefaultKey | Gets an ARM expression for the root namespace key of the Event Hub namespace. |
-| GetKey | Gets an ARM expression for a named key on this event hub. |
+| DefaultKey | Gets an ARM expression for the default namespace connection string of the Event Hub namespace. |
+| GetKey | Gets an ARM expression for the connection string of a named authorization rule on this event hub. |
 
 #### Example
 
@@ -67,6 +67,14 @@ let secondHub = eventHub {
     link_to_namespace "allmyevents"
     partitions 1
     message_retention_days 1
-    capture_to_storage myStorageAccount "mycontainer"
+    capture_to_storage storage "mycontainer"
+}
+
+let deployment = arm {
+    location Location.NorthEurope
+    add_resource primaryHub
+    add_resource secondHub
+    output "EventHubDefaultConnectionString" primaryHub.DefaultKey
+    output "EventHubFirstRuleConnectionString" (primaryHub.GetKey "FirstRule")
 }
 ```