integration-docs: Update Notion for new doc format.

Part of zulip#29592.

templates/zerver/integrations/notion.md

@@ -1,32 +1,20 @@
-Get Zulip notifications for your Notion database via Zapier!
+# Zulip Notion integration
 
-1. {!create-channel.md!}
+Get Zulip notifications for your Notion pages and databases via Zapier!
+
+{start_tabs}
 
 1. {!create-an-incoming-webhook.md!}
 
-1. Create an account on [Zapier](https://zapier.com).
+1. Continue with step 3 of the [Zapier documentation][1] to finish
+   integrating Zulip with Notion.
 
-1. [Click here](https://zapier.com/developer/public-invite/8304/bb0e9784d171eb44762c1bef4fcba2df/)
-   and then click **Accept Invite & Build a Zap**.
+!!! tip ""
 
-1. Click **Create Zap** in the upper left.
+    You can repeat the above process and create Zaps for different projects
+    and/or different kinds of Notion events that you'd like to be notified
+    about in Zulip.
 
-1. Now select **Notion** as the trigger app and choose an event. For
-   example, you can choose **New Database Item** as the event.
-
-1. After this, you will be asked to connect your **Notion** account.
-   Follow the instructions to do so.
-
-1. After connecting your account, you will be asked to select a
-   database for which you want to get notifications.
-   You will then be asked to test the trigger. If the test is
-   successful, you can proceed to the next step.
-
-1. Continue with step 7 of the [Zapier documentation][1] to
-   finish integrating Zulip with Notion.
-
-You can repeat the above process and create Zaps for different databases
-and/or different kinds of Notion events that you'd like to be notified
-about in Zulip.
+{end_tabs}
 
 [1]: ./zapier