I was wondering if there was an argument I could add to my _site.yaml file so that the rendered nav would have class = nav nav-tabs for formatting by Bootstrap (like this).

I thought there was a class: argument I could add under the navbar: section, or something like that, but I can't seem to find any documentation.

Here's what my current _site.yaml looks like, if that's relevant:

name: "my-website"
output_dir: docs
navbar:
  title: "My Website"
  left:
    - text: "Home"
      icon: fa-house
      href: index.html
    - text: "About"
      icon: fa-circle-info
      href: about.html
output:
  html_document:
    css: custom.css
    includes:
      in_header: header.html
      after_body: footer.html