docs/alerting:add missing step in tutorial (#108168)

* docs/alerting:add missing step in tutorial

* format

docs/sources/tutorials/alerting-get-started-pt2/index.md

@@ -182,6 +182,10 @@ Create a notification policy if you want to handle metrics returned by alert rul
    {{< admonition type="note" >}}
    If you don’t have any contact points, add a [Contact point](https://grafana.com/tutorials/alerting-get-started/#create-a-contact-point).
    {{</ admonition >}}
+1. Enable Continue matching:
+
+   Turn on **Continue matching subsequent sibling nodes** so the evaluation continues even after one or more labels (i.e. `device` label) match.
+
 1. Click **Save Policy**.
 
    This new child policy routes alerts that match the label `device=desktop` to the Webhook contact point.