rename TDH to part 1, and add placeholder text to last scenario

data/campaigns/The_Dark_Hordes.cfg

@@ -2,7 +2,7 @@
 	id=dark_hordes
 	rank=20
 	#textdomain wesnoth-tdh
-	name= _ "The Dark Hordes"
+	name= _ "The Dark Hordes (Part 1)"
 	define=CAMPAIGN_THE_DARK_HORDES
 	first_scenario=A_New_Chance
 	difficulties=EASY,NORMAL,HARD

data/scenarios/The_Dark_Hordes/Underground_Pool.cfg

@@ -218,6 +218,11 @@
 		description=Gwiti Ha'atel
 		message= _ "If there is anything to dread here, it is me. Now, onward!"
 		[/message]
+		[message]
+		speaker=Gwiti Ha'atel
+		caption="End of part 1"
+		message= _ "Gwiti's adventures will continue in another instalment of The Dark Hordes."
+		[/message]
 		[endlevel]
 		result=victory
 		[/endlevel]