This fixes the "last changed" time for files on GitHub. Note that this
appears to be in accordance with the shadow DOM specification, but I
can't find a line that neatly says it. Though on Google's post about
shadow DOM v1 it says:
> "the element's shadow DOM is rendered in place of its children."
https://web.dev/shadowdom-v1/#creating-shadow-dom-for-a-custom-element