Migrate to Symfony framework

public/playing.php

spotify/lib.php

spotify/spotify.php

src/Controller/.gitignore

src/Controller/AuthenticationController.php

src/Controller/DefaultController.php

src/Controller/NowPlayingController.php

src/Controller/PlaylistController.php

src/Entity/.gitignore

src/Kernel.php

src/Service/SpotifyApiService.php

src/Service/SpotifyPlaylistService.php

symfony.lock

templates/base.html.twig

templates/now-playing/index.html.twig

templates/playlist-generator/index.html.twig

templates/playlist-generator/view.html.twig

tests/bootstrap.php

translations/.gitignore

webpack.config.js