Update CHANGELOG.md

Author: spacemanspiff2007

CHANGELOG.md

@@ -1,14 +1,16 @@
 # Changelog
 
+## 1.21.9
+
+- Fixed crash when documenting ParamSpecArgs
+
 ## 1.21.7
 
 - Fixed a bug where if a class has an attribute and a constructor argument with the same name, the constructor argument
   type would be rendered incorrectly (issue 308)
 
 - Fixed napoleon handling of numpy docstrings with no specified return type.
 
-- Fixed crash when documenting ParamSpecArgs
-
 ## 1.21.6
 
 - Fix a `Field list ends without a blank line` warning (issue 305).