Yeah, there is no standard.

If you read the README.md file, you'll stumble onto the next paragraph right at its start.

This is a basic layout for Go application projects. It's not an official standard defined by the core Go dev team; however, it is a set of common historical and emerging project layout patterns in the Go ecosystem. (...)

I don’t like this repo and I’ve been recommending people avoid it for years.

Unless you have a better reference that you can provide in place of this one, I don't think you're doing anyone any good. People use these documents for guidance, and no guidance at all is clearly not a better alternative to a concrete example whose worst traits is not fitting someone's vague, subjective opinion.