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

code/modules/library/lib_machines.dm

@@ -20,6 +20,7 @@
 	icon_screen = "library"
 	icon_keyboard = null
 	circuit = /obj/item/circuitboard/computer/libraryconsole
+	desc = "Checked out books MUST be returned on time."
 	var/screenstate = 0
 	var/title
 	var/category = "Any"
@@ -161,6 +162,7 @@ GLOBAL_LIST(cachedbooks) // List of our cached book datums
 // It's December 25th, 2014, and this is STILL here, and it's STILL relevant. Kill me
 /obj/machinery/computer/libraryconsole/bookmanagement
 	name = "book inventory management console"
+	desc = "Librarian's command station."
 	var/arcanecheckout = 0
 	screenstate = 0 // 0 - Main Menu, 1 - Inventory, 2 - Checked Out, 3 - Check Out a Book
 	verb_say = "beeps"
@@ -498,6 +500,7 @@ GLOBAL_LIST(cachedbooks) // List of our cached book datums
 	name = "scanner control interface"
 	icon = 'icons/obj/library.dmi'
 	icon_state = "bigscanner"
+	desc = "It servers the purpose of scanning stuff."
 	anchored = TRUE
 	density = TRUE
 	var/obj/item/book/cache		// Last scanned book
@@ -554,6 +557,7 @@ GLOBAL_LIST(cachedbooks) // List of our cached book datums
 	name = "book binder"
 	icon = 'icons/obj/library.dmi'
 	icon_state = "binder"
+	desc = "Only intended for binding paper products."
 	anchored = TRUE
 	density = TRUE
 	var/busy = FALSE