v6.21.0

Author: rashtao

Diff for: ChangeLog.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 
 ## [Unreleased]
 
+## [6.21.0] - 2023-03-07
+
+- added `x-arango-driver` header (DE-479)
+
 ## [6.20.0] - 2022-11-29
 
 - ArangoSearch cache (#472)