Got an App working inside Gatsby project

I needed to create a /src/pages/app/[...].js "router" to handle requests for App like stuff, but it wasn't too bad. The details are in this guide: Client-only Routes & User Authentication. Definitely took some thinking, but well worth it.

The Socket.IO stuff that I was using made it a little harder. I needed to specify the Socket URL (with a Port) and do some configuring so that CORS knew it was Okay: Handling CORS