docs: def find_copies(input_dir, exclude_list):
      """
      find files that are not templates and not
      in the exclude_list for copying from template to image
      """
      copies = []
  
      def copy_finder(copies, dirname):
          for obj in os.listdir(dirname):
              pathname = os.path.join(dirname, obj)
              if os.path.isdir(pathname):
                  continue
              if obj in exclude_list:
                  continue
              if obj.endswith('.mustache'):
                  continue
  
              copies.append(os.path.join(dirname, obj))
  
      dir_visitor(
          input_dir,
          functools.partial(copy_finder, copies)
      )
      return copies