update changelog

changelog

@@ -118,6 +118,8 @@ Version 1.13.0-dev:
    * enable side_for= in key [message] with [option]s.
    * Fixed mouse tracking issue with workaround by changing the default window
      resolution for OS X to 800 x 600 (bug #20332).
+   * added [effect] apply_to=fearless/healthy which is now used by healty/fearless 
+     traits instead of hardcoding the id of those traits in c++.
  * Miscellaneous and bug fixes:
    * replace 'fight_on_without_leader'=yes/no with defeat_condition=no_leader/
      no_units/always/never which allows the wml developer to decide when a side