FWIW I usually don't structure my Go projects this way unless they're very very small. This is what I usually do for anything larger than 2-3 files:

  ├── cmd
  │   └── binary-name
  │       └── main.go (may subpackage for things like CLI porcelain, etc)
  ├── go.mod
  └── internal
      └── app.go (and subpackages, etc)