Update hash as you scroll

[bertday]

This is a fantastic guide for better public-interest technology—a big thank you to USDS for the work and vision that went into this!

I had one small suggestion, which was that the hash (e.g. #play-7) could update each time you scroll to a new play. The user story I had in mind was:

• You're scrolling and land on a play you think is interesting and want to share
• You share the URL with someone, or post to social media
• The person/audience you share it with clicks and lands directly on that play

It looks like there's already a listener on scrolling that highlights the current play in the top-level nav, so maybe the hash update could happen in that hook? I'd be happy to try a PR for this if it seems helpful!

Robert