add advanced options for captions download format

ui/src/app/interfaces/download.ts

@@ -10,6 +10,9 @@ export interface Download {
   playlist_item_limit: number;
   split_by_chapters?: boolean;
   chapter_template?: string;
+  subtitle_format?: string;
+  subtitle_language?: string;
+  subtitle_mode?: string;
   status: string;
   msg: string;
   percent: number;

ui/src/app/interfaces/formats.ts

@@ -75,7 +75,7 @@ export const Formats: Format[] = [
   },
   {
     id: 'captions',
-    text: 'Captions (EN, VTT)',
+    text: 'Captions',
     qualities: [{ id: 'best', text: 'Best' }],
   },
 ];