Update Cluster Stats API documentation

Author: dev2007

docs/reference/cluster/stats.asciidoc

@@ -25,6 +25,7 @@ Returns cluster statistics.
 
 * If the {es} {security-features} are enabled, you must have the `monitor` or
 `manage` <<privileges-list-cluster,cluster privilege>> to use this API.
+
 [[cluster-stats-api-desc]]
 ==== {api-description-title}