Fallback to vanillaJS due to React taking a significant
amount of rendering time when we wanted to only update
two classes on the navigation bar.
In addition to that, turns out Firefox has a decade-old
bug related to history.replaceState that causes it to
leak memory. This is a known issue and it's not going
to be fixed.
Our solution is to just get rid of the history.replaceState
and not update the URL when you're scrolling.
Tough luck, but hey, not gonna fix a decade old bug for a
simple throw-away website.
