proposal: Add a comment with the URL of the deployed page

[thiagocrepaldi]

Checklist

• I am using the latest version of this action.
• I have read the latest README and followed the instructions.
• I have read the latest GitHub Actions official documentation and learned the basic spec and concepts.

Describe your proposal

One trouble I had on my first run was to find out what URL the gh-pages would be available at

Describe the solution you'd like

To make that easier, this action could post a comment saying "The deploy page is available at http://..." in a way users can click and visit the recently deployed page

Describe alternatives you've considered

No response

Additional context

No response