Docs auto dark theme does not work in Firefox

Created by: felixfbecker

https://docs.sourcegraph.com/ is not dark using dark theme in Firefox if set to Auto and the OS theme is dark. It works on https://sourcegraph.com/search though.

window.matchMedia('(prefers-color-scheme: dark)').matches

returns false.

It returns true on https://sourcegraph.com/search.

Maybe the reason could be that https://sourcegraph.com/search sends a color-theme <meta> tag, and the docs do not?