adds wood planks to Cargo ordering

Only 30, and 15 points, which is more expensive than metal. Wood in
space is rare!

code/datums/supplypacks.dm

@@ -1149,6 +1149,13 @@ var/list/all_supply_groups = list(supply_emergency,supply_security,supply_engine
 	cost = 10
 	containername = "glass sheets crate"
 
+/datum/supply_packs/materials/wood30
+	name = "30 Wood Planks Crate"
+	contains = list(/obj/item/stack/sheet/wood)
+	amount = 30
+	cost = 15
+	containername = "wood planks crate"
+
 /datum/supply_packs/materials/cardboard50
 	name = "50 Cardboard Sheets Crate"
 	contains = list(/obj/item/stack/sheet/cardboard)