Docs: Add footnote about full-featured version with zoom and pan controls

app.py

@@ -131,5 +131,16 @@ with gr.Blocks(title="Mermaid Diagram Renderer", theme=gr.themes.Soft()) as demo
         outputs=[rendered_image, output_image, status_text]
     )
 
+    gr.Markdown(
+        """
+---
+<sub>
+This version is a simplified version of <a href="https://github.com/chunhualiao/mermaid-rendering" target="_blank">https://github.com/chunhualiao/mermaid-rendering</a>.<br>
+The full version has more control of previewed diagrams, such as zoom and pan operations.
+</sub>
+""",
+        elem_id="footnote",
+    )
+
 if __name__ == "__main__":
     demo.launch()