docs: function addDescriptionToHead( head, options ) {
    if ( !options || !options.config || typeof options.config.description !== 'string' ) {
      return false;
    }
  
    if ( !Array.isArray( head.children ) ) {
      head.children = [];
    }
    for ( let i = 0; i < head.children.length; i++ ) {
      const child = head.children[ i ];
      if ( child.type !== Tree.ELEMENT ) continue;
      if ( child.name.toLowerCase() != 'meta' ) continue;
      if ( !child.attribs ) continue;
      if ( typeof child.attribs.name !== 'string' ) continue;
      if ( child.attribs.name.toLowerCase() === 'description' ) {
        // There is already a description. We don't add a new one.
        return false;
      }
    }
    head.children.push( {
      type: Tree.ELEMENT,
      name: 'meta',
      attribs: {
        name: 'description',
        content: options.config.description
      }
    } );
    return true;
  }