2 more showcases

As discussed in pull request https://github.com/HaxeFlixel/haxeflixel.com/pull/58, I made new images for the 2 showcases I added. Since the featured images and non-featured images aren't the exact same ratio, I kept them 500x260.

If I find extra-time, I'll leave a message on feature https://github.com/HaxeFlixel/haxeflixel.com/issues/60 when starting implementing it.