Dark theme for Qt online documentation

Out of all Qt's subdomains, https://doc.qt.io sees the most views and time spent browsing. Many users find a darker color scheme easier on eyes, especially during late-night coding sessions.

As part of our ongoing efforts to improve your doc-reading experience, doc.qt.io now sports a new dark theme:

If you have selected a system-wide option to prefer a dark theme, doc.qt.io follows that automatically. You can also toggle the theme on the website to override this default setting, by clicking the corresponding icon on the right side of the header. If you do, the new preference is saved to your browser's local storage.

Hope you'll find it useful - feedback is always welcome!

Try it out!