Resolve alerts from reveal.js being out of date

[jenlampton]

This project might be managed with npm?

I tried to update all the things using npm but it looks like we're in the classic dependency circle, so it won't update. I'm tempted to just reinstall reveal.js over whatever is here now instead, but wanted to open this ticket just incase anyone else wanted to have this fight with the package manager first :)

[jenlampton]

Here's some docs on upgrading reveal: https://revealjs.com/upgrading/