README update
Convenience methods on battle entities to determine whether

they are a player or monster
When text fragment.removeFromPlay() is called

unbind all listeners
move the text fragment to a position way off screen so it won't be displayed.
Battle entities have hitboxes

when text fragments collide with them, damage is resolved.
Note added for a future refactor
README update
README update
Ensure fragment damage resolved on impact of fragment with battle entity