update changelog

Author: haschek

CHANGELOG.md

@@ -33,6 +33,9 @@ This is a major release, and it might be not compatible with your current usage
     -   function to calculate the difference between 2 colors using the simple CIE76 formula
 -   `textToColorHash()`
     -   function to calculate a color from a text string
+-   new icons
+    -   `artefact-task-sqlupdatequeryoperator`
+    -   `artefact-task-customsqlexecution`
 
 ### Removed