Adds an OOC sign, to be used on roleplay servers to give environmental descriptions (like "Footsteps are going off into the distance", There is a faint smell of apple pie", stuff like that)

Players can claim one with the /rps command (short for roleplay sign).

Despite what the tooltip says, it can be edited by right-clicking it with an empty hand, there's no need to have a writing item.

Also, unlike normal signs, this one can be viewed from both sides!