add tag to xdcr mobile page

Author: iamfortune

modules/server-compatibility/pages/server-compatibility-xdcr-mobile.adoc

@@ -3,6 +3,7 @@
 ifdef::show_edition[:page-edition: {release}]
 ifdef::prerelease[:page-status: {prerelease}]
 :page-role:
+:page-status: Sync Gateway 4.0
 :description: pass:q[Enable active-active deployments between mobile clusters using bi-directional Cross Data Center Replication (XDCR) with Sync Gateway 4.0.]
 :keywords: bi-directional xdcr, active-active, version vectors, mobile clusters, disaster recovery, zero downtime, revision tracking, sync gateway 4.0
 :idprefix: