Merge pull request #614 from Citadel-Station-13/upstream-merge-26521

[MIRROR] Fixes templates/ruins not updating area list

code/game/area/areas.dm

@@ -42,6 +42,7 @@
 
 	var/has_gravity = 0
 	var/noteleport = 0			//Are you forbidden from teleporting to the area? (centcomm, mobs, wizard, hand teleporter)
+	var/hidden = FALSE 			//Hides area from player Teleport function.
 	var/safe = 0 				//Is the area teleport-safe: no space / radiation / aggresive mobs / other dangers
 
 	var/no_air = null

code/game/area/areas/holodeck.dm

@@ -3,6 +3,7 @@
 	icon_state = "Holodeck"
 	dynamic_lighting = DYNAMIC_LIGHTING_DISABLED
 	flags = 0
+	hidden = TRUE
 
 	var/obj/machinery/computer/holodeck/linked
 	var/restricted = 0 // if true, program goes on emag list

code/game/area/areas/ruins.dm

@@ -4,6 +4,7 @@
 	name = "\improper Unexplored Location"
 	icon_state = "away"
 	has_gravity = 1
+	hidden = TRUE
 
 
 /area/ruin/unpowered