Add audio normalization docs and translations

Document Audio Normalization (EBU R128) in README and translated READMEs, and add corresponding localization keys and help text in ytsage language files. Updates include README.md, readme-translations (ar,de,es,fr,hi,id,it,ja,pl,pt,ru,tr,zh) and ytsage/languages JSON files to explain the feature and note that normalization requires re-encoding and forcing a specific audio format (e.g. MP3 or M4A).

ytsage/languages/id.json

@@ -326,6 +326,8 @@
     "format_mkv": "MKV (Kaya fitur)",
     "audio_format_settings": "Pengaturan Format Audio",
     "force_audio_format": "Paksa format audio untuk unduhan khusus audio",
+    "audio_normalization": "Normalisasi Audio (EBU R128)",
+    "audio_normalization_help": "Jika diaktifkan, trek audio akan dinormalisasi. Catatan: Ini memerlukan pengkodean ulang, jadi format audio tertentu (seperti MP3 atau M4A) harus dipaksakan.",
     "preferred_audio_format": "Format audio pilihan:",
     "force_audio_format_help": "Saat diaktifkan, unduhan khusus audio akan dikonversi ke format pilihan Anda. Ini hanya berlaku saat mengunduh format audio.",
     "audio_format_best": "Terbaik (Tanpa konversi)",
@@ -619,4 +621,4 @@
     "update_failed": "❌ Pembaruan gagal: {error}",
     "check_failed": "Gagal memeriksa pembaruan. Harap periksa koneksi internet Anda."
   }
-}
+}