add ignore layer command to display stacking order (#2719)

lib/extensions/display_stacking_order.py

@@ -5,6 +5,7 @@
 
 import inkex
 
+from ..commands import add_layer_commands
 from ..i18n import _
 from ..svg.tags import INKSCAPE_GROUPMODE, INKSCAPE_LABEL
 from .base import InkstitchExtension
@@ -28,6 +29,8 @@ class DisplayStackingOrder(InkstitchExtension):
                 position = next(path.end_points)
                 self.insert_stacking_num(layer, i + 1, position)
 
+        add_layer_commands(layer, ["ignore_layer"])
+
         # remove layer if empty
         if len(layer) == 0:
             self.svg.remove(layer)