Ensure a blank line between error and usage output
cmd/
It's a Go convention that main packages (one per each binary produced) are scoped under `cmd/`. https://github.com/github/go-lang/blob/master/docs/style-guide.md#directory-structure-and-filenames-layout
`make site-docs`: 1. checks out the `gh-pages` branch into the `site/` directory; 2. regenerates `.md` help pages using Cobra; 3. commits and publishes updates.