Add new image showing the UCP grant model (#195)

datacenter/ucp/2.2/guides/admin/manage-users/grant-permissions.md

@@ -13,6 +13,8 @@ to a set of resources (collection). Each grant is a 1:1:1 mapping of
 subject, role, collection. For example, you can grant the "Prod Team" 
 "Restricted Control" permissions for the "/Production" collection.
 
+![](../../images/ucp-grant-model.png)
+
 The usual workflow for creating grants has four steps.
 
 1.  Set up your users and teams. For example, you might want three teams,