add dcdm5.shader, which attempts to fix the missing texture in dcdm5 left in by Valve

zpak001.pk3dir/scripts/dcdm5.shader

@@ -0,0 +1,13 @@
+unnamed2
+{
+
+	{
+		map $lightmap
+		rgbGen identity
+	}
+	{
+		map +0dmcbtn
+		tcMod transform 0.34 0 0 0.34 0.08 0.25
+		blendFunc filter
+	}
+}