as seen (currently 2026-01-09) here: https://minite.st/docs/
you can't click on Minitest in the sidebar to see the doco for the top level namespace. All that does is show/hide the classes/modules within Minitest.
To see the Minitest doco, you must click one of those and then click up to Minitest at the top of the doco where it shows the full namespace for the class/module.