update tutorial
update tutorial

garaboo/canvas-game-bootstrap,jekkos/elektrofried,hksong/canvas-game-bootstrap,derrideanauthor/canvas-game-bootstrap,hksong/canvas-game-bootstrap,sole/canvas-game-bootstrap,ByQwert/2d-canvas-game,ByQwert/2d-canvas-game,garaboo/canvas-game-bootstrap,derrideanauthor/canvas-game-bootstrap,jlongster/canvas-game-bootstrap