update load_from_doctags usage

app.py

@@ -124,13 +124,12 @@ def model_inference(
         yield cleaned_output
 
     if any(tag in doctag_output for tag in ["<doctag>", "<otsl>", "<code>", "<chart>", "<formula>"]):
-        doc = DoclingDocument(name="Document")
         if "<chart>" in doctag_output:
             doctag_output = doctag_output.replace("<chart>", "<otsl>").replace("</chart>", "</otsl>")
             doctag_output = re.sub(r'(<loc_500>)(?!.*<loc_500>)<[^>]+>', r'\1', doctag_output)
 
         doctags_doc = DocTagsDocument.from_doctags_and_image_pairs([doctag_output], images)
-        doc.load_from_doctags(doctags_doc)
+        doc = DoclingDocument.load_from_doctags(doctags_doc, document_name="Document")
         yield f"**MD Output:**\n\n{doc.export_to_markdown()}"
 
 examples=[[{"text": "Convert this page to docling.", "files": ["example_images/2d0fbcc50e88065a040a537b717620e964fb4453314b71d83f3ed3425addcef6.png"]}],