Add `Room#desc_name`, `Room#desc_short`
Add `Room#desc_name`, `Room#desc_short`

Those methods will be implemented by the subclasses. `Room#desc_name`
returns the name of the dungeon, while `Room#desc_short` returns a short
description of the room.

The methods will provide ways for orientation and reference to other
rooms trough narration.

mbrand12/t10