add documentation

app.py

@@ -428,8 +428,13 @@ examples = [
 ]
 
 with gr.Blocks(css=CSS) as demo:
-    gr.Markdown("# Document Question Answer Comparator Engine")
-    gr.Markdown("This space compares some of the latest models that can be used commercially.")
+    gr.Markdown("# Document Question Answer Comparator")
+    gr.Markdown("""
+This space compares some of the latest models that can be used commercially.
+- [LayoutLM](https://huggingface.co/impira/layoutlm-document-qa) uses text/layout and images. Uses tesseract for OCR. 
+- [Donut](https://huggingface.co/naver-clova-ix/donut-base-finetuned-docvqa) OCR free document understanding. Uses vision encoder for OCR and a text decoder for providing the answer.  
+- [Textract Query](https://docs.aws.amazon.com/textract/latest/dg/what-is.html) OCR + document understanding solution of AWS.
+""")
 
     document = gr.Variable()
     example_question = gr.Textbox(visible=False)