Name: set_night_desc - set the night description in a room

Syntax:
	#include <room2.h>
	set_night_desc(string night_desc)

Description:
	The set_night_desc call sets the night description in a room. The
	night description is displayed after the long description when a
	player enters the room or types 'look' and if it is night.

Return value: none

Examples:
	set_night_desc("It is loomy and you feel uncomfortable.\n");

See also: room/set_day_desc, room/set_long, room/query_night_desc