Add dofile for Mineclonia menu icon PNG

menu/icon.png.do

@@ -0,0 +1,15 @@
+#!/bin/sh
+set -eu
+
+SVG_FILE=${2%.png}.svg
+
+# How crisp a Minetest menu icon appears is influenced by image height
+# and width. Low resolutions lead to blurry edges, as Minetest scales
+# menu icons up. High resolutions lead to jagged edges, as Minetest
+# scales menu icons down. Height & width of 72 pixes seem to work.
+>&2 inkscape \
+	--file="${SVG_FILE}" \
+	--export-png="${3}" \
+	--export-area-page \
+	--export-height 72 \
+	--export-width 72 \