updated version vector docs to add actors

Author: iamfortune

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

@@ -54,9 +54,9 @@ Each cluster maintained its own revision tree, making it impossible to preserve
 
 Version vectors provide a proven mechanism for tracking causality in distributed systems.
 
-A version vector consists of logical clocks maintained by each component in the distributed environment.
-Sync Gateway, XDCR, and Couchbase Lite all operate as independent components.
-Each component increments its own count when making changes, creating a vector that captures the complete update history across all clusters.
+A version vector consists of logical clocks maintained by each component capable of updating documents in the distributed environment.
+Each instance of Couchbase Lite represents its own component in the version vector, while Sync Gateway and XDCR interact with the component associated with the cluster-specific Couchbase Server bucket.
+Each component increments its own count when making changes, creating a vector that captures the complete update history across all participating actors.
 
 This architectural change enables: