title: How to handle file uploads in a `gatsby js` project?
body: <p>There is an excellent <a href="https://www.netlify.com/blog/2017/07/20/how-to-integrate-netlifys-form-handling-in-a-react-app/" rel="nofollow noreferrer">article</a> explain how to handle form submission in a <code>Gatsby Js</code> project hosted on <code>netlify</code>. However it's only about text values submission, how about the form includes some file inputs?</p>
  
  <p>Any one can shed some light here?</p>