merge source (#3)

* Added Discord timeout

* Add getOptions in plugin util

* Mutex in ffmpeg conversion (only supports one command at a time)

* Add menu customization in plugin system

* Add ytpl package (playlist info)

* Handle ffmpeg metadata flags when metadata is not present

* Only use artist in file name if present

* Export sendError method

* Handle image not present in metadata util

* Add downloader utils (getFolder and default menu label)

* Pass (optional) existing metadata and subfolder in mp3 converter

* Add listener to download playlist

* Add custom menu in downloader plugin ("download playlist" item)

* nit: fix main CSS style

* Only set the "enable" item in menu if plugin not enabled

* Navigation plugin: inject HTML once CSS is loaded

Co-authored-by: Sem Visscher <semvisscher10@gmail.com>
Co-authored-by: TC <th-ch@users.noreply.github.com>

youtube-music.css

@@ -5,7 +5,7 @@
 /* Allow window dragging */
 ytmusic-nav-bar {
 	-webkit-user-select: none;
-	-webkit-app-region : drag;
+	-webkit-app-region: drag;
 }
 
 iron-icon,