add comment on keyboard example

Author: evancz

examples/keyboard.elm

@@ -1,14 +1,23 @@
+-- Move a square around with the arrow keys: UP, DOWN, LEFT, RIGHT
+-- Try making it move around more quickly!
+--
+-- Learn more about the playground here:
+--   https://package.elm-lang.org/packages/evancz/elm-playground/latest/
+--
+
 import Playground exposing (..)
 
 
 main =
   game view update (0,0)
 
+
 view computer (x,y) =
   [ square blue 40
       |> move x y
   ]
 
+
 update computer (x,y) =
   ( x + toX computer.keyboard
   , y + toY computer.keyboard