Links in diagrams on /docs/ do not work

The Documentation page uses `<a>` elements in SVG images for links, however neither desktop Firefox nor desktop Chromium do anything if you click on them. Desktop Chromium does not even style them as links.

The links work if you right click > open image in new tab, or if I inline the diagram as an `<svg>` element rather than loading them via an `<img>` element.