fix: Atom 3 reference extruder to machine

The "machine" value in the atom3_extruder_0 file is set to the file name of the Atom 3 machine definition file.

resources/extruders/atom3_extruder_0.def.json

@@ -3,7 +3,7 @@
 	"name": "Extruder 1",
 	"inherits": "fdmextruder",
 	"metadata": {
-		"machine": "Atom 3",
+		"machine": "atom3",
 		"position": "0"
 	},