Add subdirectories to engine/ similar to pokecrystal

engine/slots/game_corner_slots2.asm

@@ -0,0 +1,31 @@
+AbleToPlaySlotsCheck:
+	ld a, [wSpriteStateData1 + 2]
+	and $8
+	jr z, .done ; not able
+	ld b, COIN_CASE
+	predef GetQuantityOfItemInBag
+	ld a, b
+	and a
+	ld b, (GameCornerCoinCaseText_id - TextPredefs) / 2 + 1
+	jr z, .printCoinCaseRequired
+	ld hl, wPlayerCoins
+	ld a, [hli]
+	or [hl]
+	jr nz, .done ; able to play
+	ld b, (GameCornerNoCoinsText_id - TextPredefs) / 2 + 1
+.printCoinCaseRequired
+	call EnableAutoTextBoxDrawing
+	ld a, b
+	call PrintPredefTextID
+	xor a
+.done
+	ld [wCanPlaySlots], a
+	ret
+
+GameCornerCoinCaseText::
+	TX_FAR _GameCornerCoinCaseText
+	db "@"
+
+GameCornerNoCoinsText::
+	TX_FAR _GameCornerNoCoinsText
+	db "@"