/**
* Is called upon if a page could not be found;
* Renders the error 404 page.
*
* @function
* @see module:middleware
* @module middleware/pageNotFound
* @param {Object} req - Express request object
* @param {Object} res - Express response object
* @returns {undefined}
*/
module.exports = (req, res) => {
res.status(404);
res.render('404');
};