title: How can I include private modules when generating documentation via Cargo?
body: <p>I'm currently working on a project with Rust and Cargo. It works well, but I encounter a little issue: for code reuse, most of my project is inside a lib crate. In this crate, a lot of things is private. So when I do <code>cargo doc</code>, I just have documentation for public, exported stuff... which is actually great, because it's easy to see what is exported and what is not.</p>
  
  <p>But I have to admit: I miss a complete documentation of the whole project, for development purpose...</p>