add QFI example

[oameye]

Checklist

Thank you for contributing to Tutorials for Quantum Toolbox in Julia! Please make sure you have finished the following tasks before opening the PR.

• Please read Contributing to Quantum Toolbox in Julia.
• The (last update) date were modified for new or updated tutorials.
• For new tutorials, a Version Information section was added at the end and displays the output of versioninfo().
• All tutorials were able to render locally by running: make render.

Request for a review after you have completed all the tasks. If you have not finished them all, you can also open a Draft Pull Request to let the others know this on-going work.

Additional context

[oameye]

The CI run had a problem with the AD cache I used. (Locally, it can fine 🤷‍♂️ .) I removed the cache as it is not what the tutorial tries to show/teach. It should now pass CI 🤞

[oameye]

It rendered, but the deploy phase failed. Seems unrelated to the changes.

[ytdHuang]

Because this branch is from your own forked repo. So there is no write access to deploy gh-pages branch and the previews.

[oameye]

I see. I don't have access to make a branch on the this repo, right? Let me know how to proceed.

[ytdHuang]

Let me make a branch QFI in this repo, and you can change the target branch of this PR to QFI branch.