Caving harness/ Spelunking gear.

With the Caves and Cliffs update coming in the next year or so, i thought it would be appropriate to add a construction type harness to the game so players might suspend themselves below blocks. Especially in the End islands, it would be helpful on some building projects to be able to hang from the bottom of the island without falling into the void. Similarly, players would be able to climb on the 'roof' of a cave or down the steep side of a cliff. This would help in extreme terrain situations, where jumping down simply isn't an option.