Update settings.md (#7868)

Changed default setting to true for v2.16.

Signed-off-by: AWSHurneyt <[email protected]>

_observing-your-data/alerting/settings.md

@@ -54,7 +54,7 @@ Setting | Default | Description
 `plugins.alerting.alert_history_retention_period` | 60d | The amount of time to store history indexes before automatically deleting them.
 `plugins.alerting.destination.allow_list` | ["chime", "slack", "custom_webhook", "email", "test_action"] | The list of allowed destinations. If you don't want to allow users to a certain type of destination, you can remove it from this list, but we recommend leaving this setting as-is.
 `plugins.alerting.filter_by_backend_roles` | "false" | Restricts access to monitors by backend role. See [Alerting security]({{site.url}}{{site.baseurl}}/monitoring-plugins/alerting/security/).
-`plugins.alerting.cross_cluster_monitoring_enabled` | "false" | Toggles whether cluster metrics monitors support running against remote clusters.
+`plugins.alerting.cross_cluster_monitoring_enabled` | "true" | Toggles whether cluster metrics monitors support running against remote clusters.
 `plugins.scheduled_jobs.sweeper.period` | 5m | The alerting feature uses its "job sweeper" component to periodically check for new or updated jobs. This setting is the rate at which the sweeper checks to see if any jobs (monitors) have changed and need to be rescheduled.
 `plugins.scheduled_jobs.sweeper.page_size` | 100 | The page size for the sweeper. You shouldn't need to change this value.
 `plugins.scheduled_jobs.sweeper.backoff_millis` | 50ms | The amount of time the sweeper waits between retries---increases exponentially after each failed retry.