feat(content): Streamline Viminal's description (endless-sky#10890)

data/map planets.txt

@@ -5631,7 +5631,7 @@ planet Vigales
 planet Viminal
 	attributes frozen remnant "remnant primary"
 	landscape land/snow3
-	description `This cold and dreary world would certainly not be attractive to any modern settlers, but to those who were fleeing the chaos of the Alpha Wars it had the undeniable advantage of being isolated and undiscovered. Today the main reason for the continuing Remnant presence here is that this is the only world they have found where the Key Stones that enable ships to travel through certain wormholes in the Ember Waste can be found.`
+	description `This cold and dreary world would certainly not be attractive to any modern settlers, but to those who were fleeing the chaos of the Alpha Wars it had the undeniable advantage of being isolated and undiscovered. The continued Remnant presence here is due to the planet's Key Stones, which enable ships to travel through certain wormholes in the Ember Waste, and which the Remnant have not found on any other planet.`
 	spaceport `The spaceport is an enormous dome, built of the same resilient and semi-organic material as the hulls of Remnant ships. An opening at one end of the dome allows ships to fly in and out. Inside, the air is still cold, but at least you are sheltered from the violent winds that sweep across the rest of the planet's surface. Some of the locals, accustomed to the cold, walk about in their shirtsleeves as if this were a balmy summer day.`
 	shipyard Remnant
 	outfitter Remnant