Update fachhochschule-vorarlberg-author-date.csl (#5501)

A student recently pointed out to us that the sorting of works by the same author does not meet the requirements of our style. It should be sorted by author, then year, then title.

Author: cookie365

fachhochschule-vorarlberg-author-date.csl

@@ -29,7 +29,7 @@
     <category citation-format="author-date"/>
     <category field="generic-base"/>
     <summary>Citation Style of the University of Applied Sciences Vorarlberg/Austria, based on A Harvard author-date style variant, mostly german</summary>
-    <updated>2019-09-04T16:00:00+00:00</updated>
+    <updated>2021-06-12T09:00:00+00:00</updated>
     <rights license="http://creativecommons.org/licenses/by-sa/3.0/">This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License</rights>
   </info>
   <locale xml:lang="de">
@@ -400,6 +400,7 @@
   <bibliography hanging-indent="true" et-al-min="4" et-al-use-first="1">
     <sort>
       <key macro="author"/>
+      <key macro="year-date"/>
       <key variable="title"/>
     </sort>
     <layout>