Adds desc to things lacking them. (#31086)

* Desc change

* Update girders.dm

* Update valve.dm

* Update machine_stacking.dm

* Update shuttle_engines.dm

* Update pipe_dispenser.dm

* Update lib_items.dm

code/modules/mining/machine_stacking.dm

@@ -4,6 +4,7 @@
 	name = "stacking machine console"
 	icon = 'icons/obj/machines/mining_machines.dmi'
 	icon_state = "console"
+	desc = "Controls a stacking machine... in theory."
 	density = FALSE
 	anchored = TRUE
 	var/obj/machinery/mineral/stacking_machine/machine = null
@@ -60,6 +61,7 @@
 	name = "stacking machine"
 	icon = 'icons/obj/machines/mining_machines.dmi'
 	icon_state = "stacker"
+	desc = "A machine that automatically stacks acquired materials. Controlled by a nearby console."
 	density = TRUE
 	anchored = TRUE
 	var/obj/machinery/mineral/stacking_unit_console/CONSOLE
@@ -90,4 +92,4 @@
 		var/obj/item/stack/sheet/out = new inp.type()
 		out.amount = stack_amt
 		unload_mineral(out)
-		storage.amount -= stack_amt
+		storage.amount -= stack_amt