feat: playlists

[Luna-devv]

works? seems like, idk

import { Lunify, PartialUser } from '../src/lib';

const refresh_token = '';

const api = new Lunify({
    clientId: '898e127e95f24f578fdbfec93ae203cd',
    clientSecret: '',
});

(async() => {
    const access = await api.oauth.refreshToken(refresh_token);
    const user = new PartialUser(api, access);

    await user.playlists.fetch(); // or just take the return value
    const playlist = user.playlists.cache.find((playlist) => playlist.name.includes('Frau'));
    console.log(playlist.name);

    await playlist.tracks.fetch();
    console.log(playlist.tracks.cache.size);
})();