Allow export/import of playlist

[e-alfred]

It would be great to be able to import and export playlists into files so they could be saved in case of a library rescan. This could potentially also fix #644.

[anatosun]

Yep it would be great to add this feature. This app could then very well become a powerful tool which could come as a replacement for any cloud music service (e.g. Spotify, Apple Music, ...). I'm currently working on an XSLT transformation which could parse an XML file (e.g. the one from iTunes/Music app) into an SQL file which could be imported into the database.

EDIT: Here is the repo https://github.com/fwicht/itunesPlaylistToNextcloudMusic

[paulijar]

Export/import of playlists is now available on Music v0.16.0.