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/library/lib_items.dm

@@ -14,6 +14,7 @@
 	name = "bookcase"
 	icon = 'icons/obj/library.dmi'
 	icon_state = "bookempty"
+	desc = "A great place for storing knowledge."
 	anchored = FALSE
 	density = TRUE
 	opacity = 0
@@ -165,6 +166,7 @@
 	name = "book"
 	icon = 'icons/obj/library.dmi'
 	icon_state ="book"
+	desc = "Crack it open, inhale the musk of its pages, and learn something new."
 	throw_speed = 1
 	throw_range = 5
 	w_class = WEIGHT_CLASS_NORMAL		 //upped to three because books are, y'know, pretty big. (and you could hide them inside eachother recursively forever)
@@ -288,6 +290,7 @@
 	name = "barcode scanner"
 	icon = 'icons/obj/library.dmi'
 	icon_state ="scanner"
+	desc = "A fabulous tool if you need to scan a barcode."
 	throw_speed = 3
 	throw_range = 5
 	w_class = WEIGHT_CLASS_TINY