Use compute_descriptions function from zimscraperlib to set descripti…

…on and long_description

src/youtube2zim/scraper.py

@@ -33,6 +33,7 @@
 from zimscraperlib.image.presets import WebpHigh
 from zimscraperlib.image.probing import get_colors, is_hex_color
 from zimscraperlib.image.transformation import resize_image
+from zimscraperlib.inputs import compute_descriptions
 from zimscraperlib.video.presets import VideoMp4Low, VideoWebmLow
 from zimscraperlib.zim import make_zim_file
 from zimscraperlib.zim.metadata import (
@@ -820,9 +821,13 @@ def update_metadata(self):
             clean_text(self.playlists[0].description)
             if self.is_playlist and len(self.playlists) == 1
             else clean_text(main_channel_json["snippet"]["description"])
-        )
+        ) or "-"
         self.title = self.title or auto_title or "-"
-        self.description = self.description or auto_description or "-"
+        self.description, self.long_description = compute_descriptions(
+            default_description=auto_description,
+            user_description=self.description,
+            user_long_description=self.long_description,
+        )
 
         if self.creator is None:
             if self.is_single_channel: