manual: add screenshots for 2048

* These were automatically generated by Amaury Pouly

* For details read http://www.rockbox.org/irc/log-20160605#20:58:18

Change-Id: I4584b07023f5e37b13a7483e60f9d30d3c7c9d69

manual/plugins/2048.tex

@@ -1,5 +1,5 @@
 \subsection{2048}
-%\screenshot{plugins/images/ss-2048}{2048}{fig:2048}
+\screenshot{plugins/images/ss-2048}{2048}{fig:2048}
 
 2048 is a simple, addictive puzzle game played by moving tiles in around on a 4x4 grid. Tiles slide as far as possible in the direction chosen by the player each turn until they are stopped by either another tile or the edge of the grid. If two tiles of the same number collide while moving, they merge into a tile with the total value of the two tiles that collided. The resulting tile cannot merge with another the same move. After each move, a tile with the value of 2 or 4 is created in an empty spot on the grid.