code: private function addDoctrineSection(ArrayNodeDefinition $rootNode)
      {
          $rootNode
              ->children()
                  ->arrayNode('doctrine')
                      ->info('doctrine configuration')
                      ->canBeEnabled()
                      ->children()
                          ->booleanNode('enabled')->defaultTrue()->end()
                      ->end()
                  ->end()
              ->end()
          ;
      }
docs: Add doctrine section.
  
  @param ArrayNodeDefinition $rootNode