Add donation link to AppStream Metadata

Author: darkdragon-001

data/com.ranfdev.Geopard.metainfo.xml.in.in

@@ -47,6 +47,7 @@
 
   <url type="homepage">https://ranfdev.com/projects/Geopard</url>
   <url type="bugtracker">https://github.com/ranfdev/Geopard/issues/</url>
+  <url type="donation">https://github.com/sponsors/ranfdev</url>
   <content_rating type="oars-1.0" />
 
   <releases>