Update uptime monitoring notification set up instructions to use "outage" (#14444)

Updates outdated terminology for setting up Uptime notifications

Author: gaprl

docs/product/uptime-monitoring/img/issue_alert_rule_2.png

@@ -39,7 +39,7 @@ _In rare cases where Sentry is unable to perform a scheduled uptime check—such
 
 ## Notifications
 
-To start getting notifications for a new downtime issue, [configure an issue alert](/product/alerts/create-alerts/issue-alert-config/) and choose the issue category "uptime". Then choose how you'd like to be notified (via email, Slack, and so on).
+To start getting notifications for a new downtime issue, [configure an issue alert](/product/alerts/create-alerts/issue-alert-config/) and choose the issue category "outage". Then choose how you'd like to be notified (via email, Slack, and so on).
 
 ![Uptime issue alert rule configuration](./img/uptime-issue-alert-rule.png)