Adding DASH Links to the flask page

Adding Some Widgets, links to the DASH flask page.
Links like :
- Github link
- Twitter link
- Thanks, message

Find the Flask page template (likely an HTML file in a templates/ directory) that needs social links (GitHub, Twitter) and a thanks message. Look for existing navigation or footer sections. Check if there's a routes.py file to see which template is rendered. Test by running the Flask app locally to verify the links appear correctly.

索引モデルが issue の本文から書いたものです。