Add CHANGELOG entry for Laurence's doc change.

Author: alysbrooks

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Added
 
+ - Add documentation for using a custom color scheme using custom data printers.
+
 ## Fixed
 
 ## Changed
@@ -156,4 +158,4 @@
 
 ## Added
 
-- Extracted from Kaocha, and added a top-level namespace.
+- Extracted from Kaocha, and added a top-level namespace.