Update [new mine tiles]

Hey guys!

I have updated the files with some new additions. The biggest one so far is the mine cart and rails in the mine tileset, as well as some ores, some scaffolding and some more natural cave tiles. There have also been some terrain aditions for deserts, as well as some additional tiles in the exterior and interior spooky tilesets. I am sure I have forgotten to mention some additions, as there have been many little tweaks and fixes throughout the tiles. And there will be a lot more in the near future, so stay tuned!