fix(cfg): 🐛 update mark_explicit default value and improve help text

* Set default value of `mark_explicit` to `False`.
* Update help text to clarify that marking explicit tracks applies only to metadata.

tidal_dl_ng/model/cfg.py

@@ -35,7 +35,7 @@ class Settings:
     path_binary_ffmpeg: str = ""
     metadata_cover_dimension: CoverDimensions = CoverDimensions.Px320
     metadata_cover_embed: bool = True
-    mark_explicit: bool = True
+    mark_explicit: bool = False
     cover_album_file: bool = True
     extract_flac: bool = True
     downloads_simultaneous_per_track_max: int = 20
@@ -95,7 +95,7 @@ class HelpSettings:
         "The dimensions of the cover image embedded into the track. Possible values: 320x320, 640x640x 1280x1280."
     )
     metadata_cover_embed: str = "Embed album cover into file."
-    mark_explicit: str = "Mark explicit tracks with 'E' in track title."
+    mark_explicit: str = "Mark explicit tracks with '🅴' in track title (only applies to metadata)."
     cover_album_file: str = "Save cover to 'cover.jpg', if an album is downloaded."
     extract_flac: str = "Extract FLAC audio tracks from MP4 containers and save them as `*.flac` (uses FFmpeg)."
     downloads_simultaneous_per_track_max: str = "Maximum number of simultaneous chunk downloads per track."