add more info on connectors

docs/en/observability/create-observability-connectors.asciidoc

@@ -1,7 +1,8 @@
 [[cases-external-connectors]]
 = Configure external connectors
 
-You can send cases to these third-party systems:
+If you are using an external incident management system, you can integrate Elastic Observability 
+cases with that system using _connectors_. These third-party systems are supported:
 
 * {sn-itsm}
 * {sn-sir}
@@ -64,7 +65,13 @@ To update an existing connector:
 
 [discrete]
 [[close-connector-observability]]
-== Close sent cases automatically
+== Sending and closing cases
+
+To send a case to an external system, click the **Push as <connector name> incident** button from the individual case page. 
+This information is not sent automatically. If you make further changes to the shared case fields, you should push the case again.
+
+If you close cases in your external incident management system, the cases will remain open in Elastic Observability until you close them 
+manually.
 
 To close cases when they are sent to an external system, select
-*Automatically close cases when pushing new incident to external system*.
+*Automatically close cases when pushing new incident to external system* when adding a connector to a case.