Broken doc links when trailing slash

[infotroph]

The list of book versions presented at https://pecanproject.github.io/documentation works as expected and contains the expected links to https://pecanproject.github.io/documentation/develop/, https://pecanproject.github.io/documentation/latest/, https://pecanproject.github.io/documentation/v1_10_0/, and so on.

But when we add a trailing slash to the URL to get https://pecanproject.github.io/documentation/, the page loads and looks identical, but the links have an extra /documentation in them (https://pecanproject.github.io/documentation/documentation/develop, etc) and all load to the 404 page.

This has been biting me a lot because my browser, very reasonably, thinks the version with the trailing slash is the likeliest autocompletion since that's the longest common substring of all the different doc pages I visit.