code: function setDefaultSettings(settings) {
    if (!settings)
      throw new Error('Settings must be an object.')
  
    // Default settings for each project type.
    switch (settings.projectType) {
      case 'cli':
      case 'node-app':
      case 'node-lib':
        settings.platforms ??= ['node']
        break
  
      case 'lib':
        settings.platforms ??= ['browser', 'node']
        break
  
      case 'react-spa':
        settings.platforms ??= ['browser']
        settings.jsx ??= true
        settings.react ??= true
        break
  
      case 'web-lib':
        settings.platforms ??= ['browser']
        break
    }
  
    // Default supported browsers inferred by the platform.
    if (settings.platforms.includes('browsers')) {
      settings.browsers ??= [
        '>= 0.5%',
        'not ie 11',
        'not op_mini all',
      ]
    }
  
    // Default supported NodeJS inferred by the platform.
    if (settings.platforms.includes('node'))
      settings.node ??= '8.9'
  }
docs: Add missing settings with the default values.