integration-docs: Update Harbor for new doc format.

Aside from updating the doc structure, this commit
also rephrases step 4 to make it read better. The
list of supported events in step 5 is also removed.

Part of #29592.

zerver/webhooks/harbor/doc.md

@@ -1,20 +1,33 @@
+# Zulip Harbor integration
+
 Get Zulip notifications for your [Harbor](https://goharbor.io/) projects!
 
 Harbor's webhooks feature is available in version 1.9 and later.
 
+{start_tabs}
+
 1. {!create-channel.md!}
 
 1. {!create-an-incoming-webhook.md!}
 
-1. {!generate-integration-url.md!}
+1. {!generate-webhook-url-basic.md!}
 
-1. Go to your Harbor **Projects** page. Open a project and click on the **Webhooks** tab.
+1. Go to your Harbor **Projects** page, open a project, and click on the **Webhooks** tab.
 
-1. Set **Endpoint URL** to the URL constructed above and click on **Continue**. We
-   currently support the following events:
-    * pushImage
-    * scanningCompleted
+1. Set **Endpoint URL** to the URL generated above, and click on **Continue**.
+
+{end_tabs}
 
 {!congrats.md!}
 
 ![](/static/images/integrations/harbor/001.png)
+
+{% if all_event_types is defined %}
+
+{!event-filtering-additional-feature.md!}
+
+{% endif %}
+
+### Related documentation
+
+{!webhooks-url-specification.md!}