add blank material files

bshift/pbr/models/woodgibs.mdl/woodgibs.mdl.mat

@@ -0,0 +1,8 @@
+
+{
+"for" "#models/woodgibs/Image9.mdl"
+//"basecolor_map" "Image9.png"
+//"normal_map" "Image9_normal.png"
+//"metal_map" "Image9_metal.png"
+//"roughness_map" "Image9_roughness.png"
+}