Update English locale with new UI strings for playlist saving and default selections. Adds 'save_playlist' and related save messages (save_as, save_success_title, saved_successfully, save_error_title, no_videos_to_save, save_error_msg), adds default selection settings keys (defaults_settings, default_video_quality, default_subtitle_language, defaults_help), and documents the %(playlist_index)s variable in filename_format_help. Also minor formatting cleanup in the file.
oop7
3b6ac7ce81