docs: add colab link

app.py

@@ -116,7 +116,7 @@ def process_refexp(image: Image, prompt: str):
 
 title = "Demo: Donut 🍩 for UI RefExp (by GuardianUI)"
 description = "Gradio Demo for Donut RefExp task, an instance of `VisionEncoderDecoderModel` fine-tuned on [UIBert RefExp](https://huggingface.co/datasets/ivelin/ui_refexp_saved) Dataset (UI Referring Expression). To use it, simply upload your image and type a prompt and click 'submit', or click one of the examples to load them. Read more at the links below."
-article = "<p style='text-align: center'><a href='https://arxiv.org/abs/2111.15664' target='_blank'>Donut: OCR-free Document Understanding Transformer</a> | <a href='https://github.com/clovaai/donut' target='_blank'>Github Repo</a></p>"
+article = "<p style='text-align: center'><a href='https://arxiv.org/abs/2111.15664' target='_blank'>Donut: OCR-free Document Understanding Transformer</a> | <a href='https://github.com/clovaai/donut' target='_blank'>Github Repo</a> | <a href='https://colab.research.google.com/github/ivelin/donut_ui_refexp/blob/main/Fine_tune_Donut_on_UI_RefExp.ipynb' target='_parent'><img src='https://colab.research.google.com/assets/colab-badge.svg' alt='Open In Colab'/></a></p>"
 examples = [["example_1.jpg", "select the setting icon from top right corner"],
             ["example_1.jpg", "click on down arrow beside the entertainment"],
             ["example_1.jpg", "select the down arrow button beside lifestyle"],