Refactor YouTube Playlist Downloader

- Moved main execution logic to cli.py and updated imports accordingly.
- Created a new __init__.py file to export the main function from the cli module.
- Implemented the PlaylistDownloader class in downloader.py to handle playlist downloading logic.
- Added ConfigLoader class in config.py to manage configuration settings.
- Introduced PlaylistManager class in manager.py to manage multiple playlists.
- Updated encoding handling for Windows in the main execution block.
- Removed redundant code and improved overall structure for better readability and maintainability.

ytplaylist/cli.py

@@ -0,0 +1,22 @@
+import subprocess
+from .config import ConfigLoader, is_docker
+from .manager import PlaylistManager
+
+
+def update_yt_dlp(yt_dlp_path: str):
+    try:
+        subprocess.run([
+            yt_dlp_path,
+            "-U",
+        ], check=True, stdout=subprocess.DEVNULL, stderr=subprocess.PIPE, text=True)
+        print("✔ yt-dlp is up to date.")
+    except subprocess.CalledProcessError:
+        print("⚠ Could not update yt-dlp: Internet unavailable or cannot reach update server")
+
+
+def main(config_path: str = "yt-playlist-config.json"):
+    cfg = ConfigLoader(config_path)
+    if not is_docker():
+        update_yt_dlp(cfg.yt_dlp_path)
+    manager = PlaylistManager(cfg)
+    manager.run()