Add --export-extra-media option

Add an option to also download the following media:

 * series thumbnail
 * series banner (only for Originals, not for Canvas)
 * series background (only for Originals, not for Canvas)
 * chapter thumbnail
 * background music as TS files

README.md

@@ -133,6 +133,11 @@ For example, downloading Tower of God, Chapter 150 would result in the following
             │...
     ```
 
+* You can also download extra media: series banner, thumbnails, music.
+    ```ps
+    $ webtoon-downloader [url] --export-extra-media
+    ```
+
 * You can additionally export the summary, chapter-title and author-notes into text files.
 You can select the format for the output as either JSON (default) or plain text files or both.
     ```ps

pyproject.toml

@@ -13,7 +13,9 @@ requires-python = '>=3.7'
 dependencies = [
   'beautifulsoup4 >= 4.10.0',
   'lxml >= 4.6.3',
+  'm3u8 >= 4.0.0',
   'Pillow >= 8.3.1',
+  'pycryptodome >= 3.19.1',
   'requests >= 2.26.0',
   'rich >= 10.10.0',
 ]

src/options.py

@@ -45,6 +45,10 @@ def initialize(self):
                             help='image format of downloaded images, available: '
                                  '(native, png, jpg)',
                             choices=['native', 'jpg', 'png'], default='native')
+        self.parser.add_argument('--export-extra-media', required=False,
+                            help='download extra media like overview images, '
+                            'thumbnails or music',
+                            action='store_true', default=False)
         self.parser.add_argument('--seperate', required=False,
                             help='[DEPRECATED] download each chapter in separate folders',
                             action='store_true', default=False)