fix append issue

app.py

@@ -40,7 +40,7 @@ def convert_file_to_img(image_file:str="",txt:str="") -> List[Image.Image] :
     """
     img_list = []
     if txt != "": 
-        image_file.append(load_img(txt))
+        img_list.append(load_img(txt,output_type="pil"))
     if image_file != "" : 
         output_path = image_file.name.rsplit('.', 1)[0] + '.pdf'
         converter.convert(image_file.name, output_path)