Add textures for air and ignore items (#5196)

builtin/game/register.lua

@@ -331,8 +331,8 @@ core.register_item(":unknown", {
 
 core.register_node(":air", {
 	description = "Air (you hacker you!)",
-	inventory_image = "unknown_node.png",
-	wield_image = "unknown_node.png",
+	inventory_image = "air.png",
+	wield_image = "air.png",
 	drawtype = "airlike",
 	paramtype = "light",
 	sunlight_propagates = true,
@@ -348,8 +348,8 @@ core.register_node(":air", {
 
 core.register_node(":ignore", {
 	description = "Ignore (you hacker you!)",
-	inventory_image = "unknown_node.png",
-	wield_image = "unknown_node.png",
+	inventory_image = "ignore.png",
+	wield_image = "ignore.png",
 	drawtype = "airlike",
 	paramtype = "none",
 	sunlight_propagates = false,