Dump GMusic playlist to JSON file

dump-playlist.js

function readRow(songRowTr) {
    let title = songRowTr.querySelector("td[data-col='title']").innerText;
    let artist = songRowTr.querySelector("td[data-col='artist']").innerText;
    let album = songRowTr.querySelector("td[data-col='album']").innerText;
    return {title, artist, album}
}

function dumpPlaylist() {
	let playlistName = document.querySelector('gpm-detail-page-header').querySelector('h2[slot=title]').innerText;
	let tracks = Array.from(document.querySelectorAll('tr.song-row')).map(songRowTr => readRow(songRowTr));
    return {name: playlistName, tracks}
}