adding description of profiles sync to overivew

Author: cmastr

src/unify/index.md

@@ -78,6 +78,15 @@ Learn about your events and identifiers on your profiles and answer questions su
 
 Visit the [Profiles Insights](/docs/unify/insights/) doc to learn more. 
 
+## Profiles Sync
+
+Profiles Sync connects identity-resolved customer profiles to a data warehouse of your choice.
+
+With a continual flow of synced profiles, teams can enrich and use these data sets as the basis for new audiences and models. Profiles Sync addresses a number of use cases, with applications for identity graph monitoring, attribution analysis, machine learning, and more.
+
+Visit the [Profiles Sync Setup](/unify/profiles-sync/profiles-sync-setup/) doc to learn more.
+
+
 ## Next steps: activate your profiles with Engage
 
 For Engage users, after you set up your identity rules and have data flowing through Unify, you can activate profiles to deliver personalized engagement experiences. Visit the [Engage docs](/docs/engage/) to learn more.