prompt: Your task is to convert the following English description into an ASCII tree format.
  
  app is a principal directory that features 2 subdirectories: [[...slug]] and api.
  At the main level, Inside '[[...slug]]', you'll find it sits empty.
  At the main level, 'api' features 3 subdirectories: exit-preview, preview, revalidate.
  Within directory hierarchy 'api > exit-preview', Inside 'exit-preview', you'll find it is currently empty.
  In nested path 'api / preview', Inside 'preview', you'll find it stands empty.
  Within directory hierarchy 'api / revalidate', The 'revalidate' directory is an empty container.
  
  
  Format your response in this style:
  ```
  docs
   +--about
   +--advanced
   +--deployment
   +--how-to
   +--learn
   +--resources
   +--security
   `--tutorial
       +--dependencies
       `--security
  ```
  
  Provide your answer wrapped in <ascii_formatted> tags.
verification_info: {"ground_truth": "app\n +--[[...slug]]\n `--api\n     +--exit-preview\n     +--preview\n     `--revalidate", "description": "app is a principal directory that features 2 subdirectories: [[...slug]] and api.\nAt the main level, Inside '[[...slug]]', you'll find it sits empty.\nAt the main level, 'api' features 3 subdirectories: exit-preview, preview, revalidate.\nWithin directory hierarchy 'api > exit-preview', Inside 'exit-preview', you'll find it is currently empty.\nIn nested path 'api / preview', Inside 'preview', you'll find it stands empty.\nWithin directory hierarchy 'api / revalidate', The 'revalidate' directory is an empty container.\n"}