Wrong chapter is displayed in title bar

[glitchassassin]

Displayed chapter seems to be off just for the initially loaded chapters - anything loaded after the fact seems fine

[glitchassassin]

looks like when you're at the beginning of a chapter, the previous chapter's intersect div actually intersects the screen (albeit under the header), which triggers the action to update the title/URL.

Since intersecting with more than 50% hinders the page load mechanism, maybe we just need to split that logic up so that the title updates at 100% intersection.