Handle Models where Config.extra is not set

[joe0BAB]

Hi! First of all, many thanks for providing this useful tool!

I'm trying to get it running, but there are two issues I'm stuck with.

First is the same as #5

The second, when I pass the path of a python file directly I get: `$pydantic2ts --module ./api/apps/folder/models.py --output test.ts --json2ts-cmd ./ui/node_modules/.bin/json2ts 2021-05-11 15:47:53,683 Finding pydantic models... 2021-05-11 15:47:53,688 Generating JSON schema from pydantic models... Traceback (most recent call last): File ".../venv/bin/pydantic2ts", line 8, in sys.exit(main()) File ".../venv/lib/python3.8/site-packages/click/core.py", line 829, in call return self.main(*args, **kwargs) File ".../venv/lib/python3.8/site-packages/click/core.py", line 782, in main rv = self.invoke(ctx) File ".../venv/lib/python3.8/site-packages/click/core.py", line 1066, in invoke return ctx.invoke(self.callback, **ctx.params) File ".../venv/lib/python3.8/site-packages/click/core.py", line 610, in invoke return callback(*args, **kwargs) File ".../venv/lib/python3.8/site-packages/pydantic2ts/cli/script.py", line 222, in main return generate_typescript_defs(module, output, json2ts_cmd) File ".../venv/lib/python3.8/site-packages/pydantic2ts/cli/script.py", line 187, in generate_typescript_defs schema = generate_json_schema(models) File ".../venv/lib/python3.8/site-packages/pydantic2ts/cli/script.py", line 144, in generate_json_schema model_extras = [m.Config.extra for m in models] File ".../venv/lib/python3.8/site-packages/pydantic2ts/cli/script.py", line 144, in model_extras = [m.Config.extra for m in models]

AttributeError: type object 'Config' has no attribute 'extra' ` If I understand the docs correctly, the Config.extra field is optional. However, right now pydantic-to-typescript does not handle this case.