docs: def add_suffix(filename, suffix):
          """
          ADD suffix TO THE filename (NOT INCLUDING THE FILE EXTENSION)
          """
          path = filename.split("/")
          parts = path[-1].split(".")
          i = max(len(parts) - 2, 0)
          parts[i] = parts[i] + suffix
          path[-1] = ".".join(parts)
          return "/".join(path)