add jellybox variants

there’s a one fan variant and a two fan variant. for now, both are only
0.4mm nozzle.

resources/variants/imade3d_jellybox_0.4.inst.cfg

@@ -0,0 +1,11 @@
+[general]
+name = 0.4 mm
+version = 2
+definition = imade3d_jellybox
+
+[metadata]
+author = IMADE3D
+type = variant
+
+[values]
+machine_nozzle_size = 0.4

resources/variants/imade3d_jellybox_0.4_2-fans.inst.cfg

@@ -0,0 +1,11 @@
+[general]
+name = 0.4 mm 2-fans
+version = 2
+definition = imade3d_jellybox
+
+[metadata]
+author = IMADE3D
+type = variant
+
+[values]
+machine_nozzle_size = 0.4