Touch 'DONE' file in completed albums

src/main.py

@@ -59,6 +59,8 @@ def main(input_dir: Path, output_dir: Path, encoder: Path):
                             print(f"Skipping '{artist.parts[-1]} / {album.parts[-1]}'")
                         else:
                             album_out.mkdir()
+                            done_file = album / 'DONE'
+                            open(done_file, 'a').close()
                             for track in album.iterdir():
                                 if track.is_file() and track.suffix.lower() == '.flac':
                                     transcode_list.append((str(track), str(album_out / f"{track.stem}.opus")))