webhooks/airbrake: Use Markdown macros for documentation.

tools/lint

@@ -582,7 +582,6 @@ def build_custom_checkers(by_lang):
             "docs/migration-renumbering.md",
             "docs/readme-symlink.md",
             "README.md",
-            "zerver/webhooks/airbrake/doc.md",
             "zerver/webhooks/appfollow/doc.md",
             "zerver/webhooks/trello/doc.md",
         }

zerver/webhooks/airbrake/doc.md

@@ -1,14 +1,8 @@
 Get Zulip notifications for your Airbrake bug tracker!
 
-First, create the stream you'd like to use for Airbrake notifications, and
-subscribe all interested parties to this stream. We recommend the
-name `airbrake`.
-
-Next, on your {{ settings_html|safe }}, create an Airbrake bot. Construct the
-URL for the Airbrake bot using the API key and stream name:
-
-`{{ external_api_uri_subdomain }}/v1/external/airbrake?api_key=abcdefgh&stream=airbrake`
+{!create-stream.md!} `airbrake`.
 
+{!create-bot-construct-url.md!}airbrake?api_key=abcdefgh&stream=airbrake`
 
 Now, go to your project's settings on the Airbrake site. Click
 on the `Integration` section. Choose `Webhook`, provide the above URL,
@@ -16,8 +10,6 @@ check `Enabled`, and save. Your Webhook configuration should look similar to:
 
 ![](/static/images/integrations/airbrake/001.png)
 
-**Congratulations! You're done!**
-
-Your messages may look like:
+{!congrats.md!}
 
 ![](/static/images/integrations/airbrake/002.png)