Harmonize buttons in the nav and automatically copy the search term to
the AI widget.
Uses "cmd k" to open the AI widget instead of search.
Touch up search results.
<!--Delete sections as needed -->
## Description
<!-- Tell us what you did and why -->
## Related issues or tickets
<!-- Related issues, pull requests, or Jira tickets -->
## Reviews
<!-- Notes for reviewers here -->
<!-- List applicable reviews (optionally @tag reviewers) -->
- [ ] Technical review
- [ ] Editorial review
- [ ] Product review
- Extract classes to utilities and components.
- Reduce number of colors used.
- Harmonize button colors.
- Restyle admonitions.
- Move **Page options** button to main article.
- Various color tweaks.
