Upgraded mineshafts and Skeleton miners

Mineshafts should have a surface entrance because all real life ones do. There should be two main ways down from this entrance. The first would be the way the miners went in, a classic staircase. The second way would be a ruined minecart track where the miners would use to better transport their findings. Both entrances would be broken and ruined and covered with cobwebs. The entrance would be a plank and wood roof held up by oak fences and cobblestone walls. This too would also be covered with cobwebs and slightly destroyed. A new mob would be added that guards these new entrances as well as the actual structure. These are called Skeleton Miners. They are much like regular skeletons but instead wield a gold pickaxe and wear a gold helmet. When killed they drop bones and have a chance of dropping their gold tools and armor, nothing too special.