mendeley: added atila to maintainers

pkgs/applications/office/mendeley/default.nix

···
     sourceProvenance = with sourceTypes; [ binaryNativeCode ];
     license = licenses.unfree;
     platforms = [ "x86_64-linux" ];
-    maintainers  = with maintainers; [ dtzWill ];
+    maintainers  = with maintainers; [ dtzWill atila ];
   };
 
 }