docs: Updated New Relic documentation.

The docs are updated to work with the new webhook and new process on
https://one.newrelic.com.

zerver/webhooks/newrelic/doc.md

@@ -1,16 +1,25 @@
-New Relic can send messages to a Zulip stream for alerts and
-deploys.
+New Relic can send messages to a Zulip stream for incidents.
 
-{!create-stream.md!}
+1. {!create-stream.md!}
 
-{!create-bot-construct-url.md!}
+1. {!create-bot-construct-url-indented.md!}
 
-Next, in your New Relic Account Settings page, click
-**Integrations**, then **Alerting notifications**. On the
-**Webhook** tab, enter the webhook URL created earlier:
+1. On [New Relic](https://one.newrelic.com),
+  select **Alerts & AI**.
 
-![](/static/images/integrations/newrelic/001.png)
+1. Navigate to **Notification channels**.
+
+1. Create a new notification channel. Select channel type of **Webhook**, choose a name (e.g. "Zulip"), enter the webhook url created earlier as **Base Url**.
+
+1. It should look like:
+  ![](/static/images/integrations/newrelic/newrelic.png)
+
+1. The webhook works with the default payload, click **Create channel**.
+
+1. After creating the channel send a test notification to make sure it works.
 
 {!congrats.md!}
 
-![](/static/images/integrations/newrelic/002.png)
+![](/static/images/integrations/newrelic/opened.png)
+![](/static/images/integrations/newrelic/ack.png)
+![](/static/images/integrations/newrelic/closed.png)

zerver/webhooks/newrelic/tests.py

@@ -84,16 +84,6 @@ No details.
             )
         self.assertIn("The newrelic webhook requires current_state be in [open|acknowledged|closed]", e.exception.args[0])
 
-    def test_missing_duration(self) -> None:
-        with self.assertRaises(AssertionError) as e:
-            self.check_webhook(
-                "incident_missing_duration",
-                "",
-                "",
-                content_type="application/json",
-            )
-        self.assertIn("The newrelic webhook requires duration in milliseconds", e.exception.args[0])
-
     def test_missing_timestamp(self) -> None:
         with self.assertRaises(AssertionError) as e:
             self.check_webhook(