added explanation for local files

SpotifyAutoPlaylistCreator.py

@@ -68,6 +68,8 @@ class SpotifyAutoPlaylistCreator:
                 break
 
             if track['is_local']:
+                # It's not possible to add a local track to a playlist using the web API.
+                # https://github.com/plamere/spotipy/issues/793#issuecomment-1082421408
                 LOGGER.info(f'Skipping local track "{track["track"]["name"]}"')
                 continue