add better gif creating script

this worked well with the “2hr youtube clone” demo

bin/to-gif-hq.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+# Convert a video file to a gif.
+# `to-gif /path/to/input.mp4 /path/to/output.gif`
+palette="/tmp/to-gif-palette.png"
+filters="fps=15"
+ffmpeg -v warning -i $1 -vf "$filters,palettegen" -y $palette
+ffmpeg -v warning -i $1 -i $palette -lavfi "$filters [x]; [x][1:v] paletteuse" -y $2
+
+# gifsicle --resize-fit-width 1000 -i animation.gif > animation-1000px.gif