docs: def expand_file_arguments():
      """ Any argument starting with "@" gets replaced with all values read from a text file.
      Text file arguments can be split by newline or by space.
      Values are added "as-is", as if they were specified in this order on the command line.
      """
      new_args = []
      expanded = False
      for arg in sys.argv:
          if arg.startswith("@"):
              expanded = True
              with open(arg[1:],"r") as f:
                  for line in f.readlines():
                      new_args += shlex.split(line)
          else:
              new_args.append(arg)
      if expanded:
          print("esptool.py %s" % (" ".join(new_args[1:])))
          sys.argv = new_args