fix undefined variable

src/arenas_lists.php

@@ -4,13 +4,15 @@ $arenas=array(
         'id'    => "tictactoe",
         'url'   => "/tictactoe",
         'title' => "Tic Tac Toe",
+        'metaDescription'   => 'Affrontements de bots au TicTacToe, morpion',
         'jsFile'=> "js.js",
         'cssFile'=> "style.css"
     ),
     array(
         'id' => "Battleship",
         'url' => "/Battleship",
-        'title' => "bataille Navale"
+        'title' => "bataille Navale",
+        'metaDescription'   => 'Affrontements de bots à la battaille navale'
     )
     
 );