docs: title of docs page is "Dark mode disabled"

[codymullins]

The title of the Docs page is "Dark mode disabled" - this started appearing when the MkDarkModeToggle was added. We're using this title in the SVG as the caption for accessibility.

Need to find out:

1. Why the addition to the SVG causes this?
2. What is the fix?
3. Does the SVG code need to change?