docs: def git_available(func):
      """
      Check, if a git repository exists in the given folder.
      """
      def inner(*args):
  
          os.chdir(APISettings.GIT_DIR)
  
          if call(['git', 'rev-parse']) == 0:
              return func(*args)
  
          Shell.fail('There is no git repository!')
          return exit(1)
      return inner