title: Cmake external ressource
body: <p>HI I'm beginning to use cmake, And  I like it a lot, I was wondering if there was a command to add an existing folder that contain input file in the build process.</p>
  
  <p>Desired structure </p>
  
  <pre><code>project/
     src/
     ressources/someinputData
  </code></pre>
  
  <p>I don't want to copy all the files on resources to the build folder.</p>