title: Add custom http response headers for files matching conditions
body: <p>I need to add a custom http header to every http response from my IIS 8.5, but only for specific file types (css, js and html). </p>
  
  <p>I've tried this solution 
  <a href="https://stackoverflow.com/questions/9522348/add-custom-header-based-on-file-type">Add custom header based on file type</a>, but it seems outdated, and I'm getting errors for bad <code>web.config</code> file.</p>
  
  <p>How it can be done on IIS 8.5?<br/>Any help will be appreciated.</p>