code: def init(directory=None):
      
      repo = repo_path(directory)
      if os.path.isdir(repo):
          raise RepositoryAlreadyExistsError(directory, repo)
  
      # Initialize repository with default template
      shutil.copytree(default_template_path, repo)
  
      message = '"Default presentation content."'
      subprocess.call(['git', 'init', '-q', repo])
      subprocess.call(['git', 'add', '.'], cwd=repo)
      subprocess.call(['git', 'commit', '-q', '-m', message], cwd=repo)
  
      return repo
docs: Initializes a Gitpress presentation repository at the specified directory.