integration-docs: Update CircleCI for new doc format.

Part of #29592.

zerver/webhooks/circleci/doc.md

@@ -1,22 +1,38 @@
+# Zulip CircleCI integration
+
 Zulip supports integration with CircleCI and can notify you of your
 job and workflow statuses. This integration currently supports using
 CircleCI with GitHub, BitBucket and GitLab.
 
+{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 project on CircleCI and click on **Project
-   Settings**. Select **Webhooks** from the list on the left.
-   Click on **Add Webhook** in the menu that opens.
+1. Go to **Project Settings** in your project on CircleCI. Select
+   **Webhooks** from the list on the left, and click **Add Webhook**.
 
 1. In the form that opens, give your webhook a name and set the
-   **Receiver URL** field to the URL constructed above. Choose the
-   desired events and click on **Add Webhook**.
+   **Receiver URL** field to the URL generated above. Choose the
+   [events](#filtering-incoming-events) you'd like to be notified about,
+   and click **Add Webhook**.
+
+{end_tabs}
 
 {!congrats.md!}
 
 ![](/static/images/integrations/circleci/001.png)
 ![](/static/images/integrations/circleci/002.png)
+
+{% if all_event_types is defined %}
+
+{!event-filtering-additional-feature.md!}
+
+{% endif %}
+
+### Related documentation
+
+{!webhooks-url-specification.md!}