a bug in the doc

[waterwoodwind]

root@f62374f19c02:~/xfastertransformer# python ./tools/opt_convert.py -i ./data/opt-1.3b-hf -o ./data/opt-1.3b-cpu
File "./tools/opt_convert.py", line 284
parser.add_argument("--weight_data_type", "-d" type=str, default="fp16", choices=["fp32", "fp16"])
^
SyntaxError: invalid syntax