chore(*): update changelog

Author: DiyanDimitrov

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes for each version of this project will be documented in this file.
 
+## 9.0.9
+- `IgxGrid`, `IgxTreeGrid`, `IgxHierarchicalGrid`
+    - The `title` attribute of the columns and the column groups is now used as `title` for the header text.
+
 ## 9.0.1
 - **Breaking Changes** 
     - Remove `$base-color` from igx-typography. The igx-typography class now inherits the parent color.