Add windows installer to appstream artifacts

This way it gets listed on apps.kde.org

org.kde.elisa.appdata.xml

@@ -223,7 +223,15 @@ SPDX-License-Identifier: CC0-1.0
   <project_group>KDE</project_group>
   <content_rating type="oars-1.0"/>
   <releases>
-    <release version="21.12.3" date="2022-03-03"/>
+    <release version="21.12.3" date="2022-03-03">
+      <artifacts>
+        <artifact type="binary" platform="win64">
+          <location>https://download.kde.org/stable/release-service/21.12.3/windows/elisa-21.12.3-1065-windows-msvc2019_64-cl.exe</location>
+          <checksum type="sha256">7362385eb522fb7015e5eebdfc13d4ae2636451200ad2e4b82b25d93227e6ce7</checksum>
+          <size type="download">102788656</size>
+        </artifact>
+      </artifacts>
+    </release>
     <release version="21.12.2" date="2022-02-03"/>
     <release version="21.12.1" date="2022-01-06"/>
     <release version="21.12.0" date="2021-12-09"/>