integrations: Add documentation for Notion-Zapier Integration.

Fixes #25314.

templates/zerver/integrations/notion.md

@@ -0,0 +1,32 @@
+Get Zulip notifications for your Notion database via Zapier!
+
+1. {!create-stream.md!}
+
+1. {!create-an-incoming-webhook.md!}
+
+1. Create an account on [Zapier](https://zapier.com).
+
+1. [Click here](https://zapier.com/developer/public-invite/8304/bb0e9784d171eb44762c1bef4fcba2df/)
+   and then click **Accept Invite & Build a Zap**.
+
+1. Click **Create Zap** in the upper left.
+
+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.
+
+[1]: ./zapier

zerver/lib/integrations.py

@@ -582,6 +582,9 @@ INTEGRATIONS: Dict[str, Integration] = {
         stream_name="commits",
     ),
     "nagios": Integration("nagios", "nagios", ["monitoring"], doc="zerver/integrations/nagios.md"),
+    "notion": Integration(
+        "notion", "notion", ["productivity"], doc="zerver/integrations/notion.md"
+    ),
     "openshift": Integration(
         "openshift",
         "openshift",