Update FAQ ToC

[kichristensen]

What does this change

Updates the ToC on the FAQ page

What issue does it fix

Closes #3053

Notes for the reviewer

An alternative solution could be to removed the ToC on the page in favor for using the one on the right provided by the theme. Please let me know what you think about that solution. The change in this PR mimics what is done on other pages, but there are pros and cons for both approaches.

Checklist

• Did you write tests?
• Did you write documentation?
• Did you change porter.yaml or a storage document record? Update the corresponding schema file.
• If this is your first pull request, please add your name to the bottom of our Contributors list. Thank you for making Porter better! 🙇‍♀️

Reviewer Checklist

• Comment with /azp run test-porter-release if a magefile or build script was modified
• Comment with /azp run porter-integration if it's a non-trivial PR