ref/* taken from ansiplay Copyright 1991, Julie Ibarra
doc/mus/* taken from textfiles.com

Usage:

    import * as ansiplay from "./ansiplay.js";

    if (ansiplay.is_playing()) {
        ansiplay.stop().then(() => ansiplay.play(url));
    } else {
        ansiplay.play(url);
    }

Multiple imports will result in multiple voices.