Support antd v5

[xrutayisire]

antd v5 is out! 🥳

It's a major new version, and it requires some little changes on this package:

• [x] Remove any references to lib folder (deleted on antd side) - Thanks @chillyistkult https://github.com/xrutayisire/react-js-cron/pull/39
• [x] New dropdown props - https://github.com/xrutayisire/react-js-cron/issues/35
• [x] Fix tsc to build types crash - https://github.com/ant-design/cssinjs/issues/55
• [x] Update stories for antd v5
• [x] Update README to explain how antd styles need to be handled (if required) - https://github.com/xrutayisire/react-js-cron/pull/37 (No override is needed with new antd v5)

Feel free to comment on this issue if you found any other things that need to be changed