title: Roxygen not generating .Rd files with directory tree
body: <p>I have main directory with R project file, project is called "knn". I have subdirectories source (contains all .R files), data (contains .csv files used in project) and man (.Rd files should go there). I also have correct DESCRIPTION and NAMESPACE (generated by Roxygen) files in main directory.</p>
  
  <p>When I use <code>roxygen2::roxygenize()</code> in my main project directory, I get <code>Loading knn</code> and no files. When I use <code>devtools::document()</code> in my main directory, I get <code>Updating knn documentation Loading knn</code>. I have no documentation or .Rd files whatsoever.</p>
  
  <p>I've even tried moving all my .R files to main directory - same results. How can I generate my documentation? What am I doing wrong?</p>