Add translation variable for transcript tab to basis for musdb

backend/de/basis.json

@@ -103,6 +103,7 @@
         "room": "Raum",
         "image": "Bild",
         "menu_items": "Menu Items",
-        "backgrounds": "Hintergr\u00fcnde"
+        "backgrounds": "Hintergr\u00fcnde",
+        "transcription": "Transkript"
     }
 }