Update urbanterror.md

Author: ivan-hc

apps/urbanterror.md

@@ -1,10 +1,16 @@
 # URBANTERROR
 
  A team-based tactical shooter based on the Quake 3 Engine.
+
+ Urban Terror™ is a free multiplayer first person shooter developed by FrozenSand, that will run on any Quake III Arena compatible engine.
+
+ This is the unofficial AppImage built from the official archive.
 
  ![](https://media.tenor.com/sj1RVz4T7wwAAAAC/urban-terror.gif)
 
  SITE: http://www.urbanterror.info
 
+ UNOFFICIAL APPIMAGE: https://github.com/ivan-hc/UrbanTerror-appimage
+
  | [Applications](https://portable-linux-apps.github.io/apps.html) | [Home](https://portable-linux-apps.github.io)
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