chore: update (German) translation

Translate-URL: https://librescore.ddns.net/projects/librescore/dl-librescore/de/

Author: Nein

src/i18n/de.json

@@ -11,7 +11,7 @@
     "title": "",
     "no_sheet_images_error": "",
     "source_code": "",
-    "download_audio": "",
+    "download_audio": "{{fileType}} Audio herunterladen",
     "full_score": "",
     "button_parent_not_found": "",
     "unknown_button_list_mode": "",
@@ -21,7 +21,7 @@
     "path_to_file": "",
     "cli_example_folder": "",
     "cli_example_file": "",
-    "download": "",
+    "download": "{{fileType}} herunterladen",
     "version": "",
     "cli_parts_message": "",
     "cli_saved_message": "",