minor fixes, added result processing

src/web/templates/index.html

@@ -71,7 +71,9 @@
 </style>
 <body>
     <form method="post" action="/submit" id="download">
-         <input type="text" name="link">
+         <input type="text" name="link" placeholder="link">
+         <input type="text" name="format" placeholder="format">
+         <input type="text" name="merge_output_format" placeholder="merge_output_format">
          <button type="submit" class="custom-btn btn-1"><span class="submit-spinner submit-spinner_hide"></span> Download</button>
     </form>
     <div class="col">