Adds synced audio to asciinema console casts.
This script finds any asciinema-player
tag having audiosrc attribute and creates a sibbling
hidden audio tag which sinchronizes with the playback
of the asciinema-player.
<link rel="stylesheet" type="text/css" href="./asciinema-player.css" />
<script src="./asciinema-player.js"></script>
<script src="./asciinema-audio.js"></script>
...
<asciinema-player
src="mycast.cast"
audiosrc="mycast.mp3"
audiotype="audio/mpeg"
/>