Use charmap in link_battle_versus_text (pret#415)

Author: LinusU

engine/battle/link_battle_versus_text.asm

@@ -13,9 +13,9 @@ DisplayLinkBattleVersusTextBox:
 	call PlaceString
 ; place bold "VS" tiles between the names
 	hlcoord 9, 8
-	ld a, $69
+	ld a, "<BOLD_V>"
 	ld [hli], a
-	ld [hl], $6a
+	ld [hl], "<BOLD_S>"
 	xor a
 	ld [wUpdateSpritesEnabled], a
 	callfar SetupPlayerAndEnemyPokeballs