When going through /getting-started, I found that the "Next" link in /architecture sends folks directly to /reference. That gave me a first impression that there was no more documentation other than the API reference. A better "next" path from /architecture would be /components. Components is already set up to send people to declarative, routing, etc. after that.
Fixing this would provide a much smoother learning curve and likely higher adoption. In my own case, hitting /reference so quickly caused me to spend an afternoon looking for alternatives to go-app before I realized what the problem was.