Update website config

[olivroy]

Prework

• [x] I understand and agree to the Contributor Code of Conduct.
• [ ] I have already submitted a discussion topic or issue to discuss my idea with the maintainer.

Related GitHub issues and pull requests

• Ref: #

Summary

The main purpose of this PR is to modernize the website look and to add a search bar. I also removed back-ticks and quotes from the contents as they are not required by pkgdown The badges change make them appear on the side of the page

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (2df5c20) 100.00% compared to head (e0be9c0) 100.00%.

:exclamation: Current head e0be9c0 differs from pull request most recent head d474033. Consider uploading reports for the commit d474033 to get more accurate results

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #151 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 28 28 Lines 1990 1990 ========================================= Hits 1990 1990 ```

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[wlandau]

Thanks, I like these improvements!

[olivroy]

Apologies for the failed build. here is a preview of the new look

[wlandau]

No worries, I fixed the _pkgdown.yaml in the PR.