Directly visiting a page doesn't work

[zopsicle]

Steps to reproduce

1. Visit https://libgit2.org/libgit2/#1.7.2/group/diff/git_diff_get_delta, or any other page for a specific documented item, by directly entering its URL in the address bar of the browser.

Expected behavior

The browser shows the content of the page, as if navigating to the page by a hyperlink linking to it.

Actual behavior

The browser only shows the header, footer, and navigation bar.