add materials (mat) files and readme.md

cstrike/models/pred_plant.mdl/pred_plant.mdl.mat

@@ -0,0 +1,8 @@
+
+{
+"for" "#models/pred_plant/hugeleaf.mdl"
+"basecolor_map" "hugeleaf.png"
+//"normal_map" "hugeleaf_normal.png"
+//"metal_map" "hugeleaf_metal.png"
+//"roughness_map" "hugeleaf_roughness.png"
+}