terranix: add sshine as maintainer

This follows becoming a maintainer:
- terranix/terranix#122

in order to make future releases.

pkgs/by-name/te/terranix/package.nix

···
     homepage = "https://terranix.org";
     license = licenses.gpl3;
     platforms = platforms.unix;
-    maintainers = with maintainers; [ mrVanDalo ];
+    maintainers = with maintainers; [
+      mrVanDalo
+      sshine
+    ];
   };
 }