Blogpost: https://blog.apify.com/how-to-turn-any-website-into-an-rss-feed-a8f9f216e1b0

page_function.js

function pageFunction(context) {
  var $ = context.jQuery;
  // All h4 headings containing date - <h4>2016-11-24</h4>
  var headings = $('.page-content h4');
  // All descriptions - <ul><li>General: ...</li>...</ul>
  var lists = $('.page-content ul');

  // Iterate thru all release notes
  var result = [];
  for (var i = 0; i < headings.length; i ++) {
    var date = headings[i].innerText;
    var description = lists[i].outerHTML;

    result.push({
      title       : date + ' Release notes',
      description : description,
      link        : 'http://apifier.com/release-notes#' + date,
      guid        : date,
      pubDate     : (new Date(date)).toUTCString()
    });
  }
  return result;
}