docs: Update Gradio example link (#5183)

Author: Sherlock113

docs/source/build-with-bentoml/gradio.rst

@@ -99,4 +99,4 @@ Follow the steps below to integrate Gradio with a BentoML Service.
    .. image:: ../../_static/img/build-with-bentoml/gradio/gradio-ui-bentoml.png
       :alt: Gradio UI for a BentoML Service
 
-Visit this `example <https://github.com/bentoml/BentoML/tree/main/examples>`_ to view the full demo code.
+Visit this `example <https://github.com/bentoml/BentoGradio>`_ to view the full demo code.