title: How to force Gatsby to redirect a specific URL path to an external site?
body: <p>I have a Gatsby site and due to some specific requirements, I need to redirect anyone who attempts to hit a specific URL path, for which there is no page, to an external site. This URL path is not a page within the site, but it's something that a user may be inclined to type due to documentation that is out of my control.</p>
  <p>Here's an example: Let's say the site is located at <a href="https://www.example.com" rel="nofollow noreferrer">https://www.example.com</a>. A user may visit <a href="https://www.example.com/puppies" rel="nofollow noreferrer">https://www.example.com/puppies</a>, which does not exist. My file structure does not contain a <code>src/pages/puppies.js</code> file. However, when that URL is entered, I need to redirect the user to another site altogether, such as <a href="https://www.stackoverflow.com">https://www.stackoverflow.com</a>.</p>