old_contents: const files = [
    require('./welcome'),
    require('./updating'),
    require('./faq'),
    require('./ping_pong'),
    require('./avatar'),
  ];
  
  const categories = {};
  for (const file of files) {
    file.category = file.category.toLowerCase();
    if (!categories[file.category]) {
      categories[file.category] = [];
    }
    categories[file.category].push(file);
  }
  
  module.exports = categories;
  
new_contents: const files = [
    require('./welcome'),
    require('./updating'),
    require('./faq'),
    require('./ping_pong'),
    require('./avatar'),
    require('./webhook'),
  ];
  
  const categories = {};
  for (const file of files) {
    file.category = file.category.toLowerCase();
    if (!categories[file.category]) categories[file.category] = [];
    categories[file.category].push(file);
  }
  
  module.exports = categories;
  
subject: Fix webhook example