Update changelog

changelog

@@ -5,6 +5,7 @@ Version 1.13.4+dev:
  * WML engine:
    * Fix some issues with [foreach]
    * Fix some issues with backstab-like weapon specials
+   * Support [effect]times=<integer>
  * Lua API:
    * wesnoth.match_unit can now take a location (rather than a unit) as
      the optional third parameter. This will cause the filter to consider
@@ -21,6 +22,10 @@ Version 1.13.4+dev:
      (where "array" is a table whose keys are all integers). This joins
      the elements of the array with commas and produces a single string
      value. eg {x = {1,2,3}} is equivalent to {x = "1,2,3"}.
+   * wesnoth.effects table can now be used to alter the behaviour of
+     built-in effects - for example, to add a new feature to
+     [effect]apply_to=attack. It also now supports effect descriptions,
+     for use by the [trait] tag.
  * Wesnoth formula engine:
    * Formulas in unit filters can now access nearly all unit attributes
    * New syntax features: