title: R Package development: how to update the 'doc' folder with new vignettes
body: <p>I noticed that, in R, when I use <code>install.packages</code> to download my own library, it will create a <code>doc</code> folder in <code>\R\3.3\win-library\PACKAGENAME\</code> in which vignette HTML files will be stored.</p>
  
  <p>However, if I use RStudio to build my package from source, this <code>doc</code> folder is not created. If it is already there, it is not updated (i.e.: it just keeps older versions of the vignettes and will not add new ones).</p>
  
  <p>Seems like an odd behaviour. Is there any way to have RStudio update the contents of the <code>doc</code> folder?</p>
  
  <p>Thank you!</p>
  
  <p>Andrew</p>