What website template does Jest use for their documentation?

I'm starting to see many javascript package documentation websites use a similar template.

Wondering what template is used here?

React Native Dropdown Picker
Jest Documentation
React Native API Docs - Also looks similar to the actual React Native documentation website

There's always that funky looking sun/moon at the top right, two big rectangular buttons to go back or forward at the bottom of each page, the package version at the top left, sometimes the algolia search in the top right