Update appdata.xml.in

Author: rodlie

src/app/appdata.xml.in

@@ -14,6 +14,12 @@
     <p>@PROJECT_DESCRIPTION@</p>
   </description>
   <releases>
+    <release date="2025-12-31" version="1.0.0-rc.3">
+      <description>
+        <p>Third release candidate for v1.0.0 is now available. Features gizmos, snapping and grid. And of course many fixes!</p>
+      </description>
+      <url type="details">https://friction.graphics/releases/friction-100-rc3.html</url>
+    </release>
     <release date="2025-08-06" version="1.0.0-rc.2">
       <description>
         <p>Second release candidate for v1.0.0 is now available.</p>