Update [stairs and living roots bridge]

Hey guys!
There has been an update to the aztec tileset that I would like to share with you!
There was a serious lack of stair variations, so I changed that by adding 4-directional stair tiles including broad stone railings. So now you can build those iconic aztec temples with stairs to each side.
I also wanted to give you more ways to make deep, mysterious jungles, so I started working on a bridge made of roots that can be placed across canyons with variable length. This root bridge is not finished yet, but I have already included the current raw version so you guys can try it out.
Apart from that there have mostly been minor additions and some polishing here and there.
Hope you like it and happy to hear feedback :)