lazyLoad props API seems incomplete

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With my understanding, lazyLoad props seem can be set to true or false like https://react-slick.neostack.com/docs/example/lazy-load this doc example which is equivalent to 'ondemand'.

But this is not clear in API doc [page](https://react-slick.neostack.com/docs/api).

If I'm correct, I'm glad to fix the API document page.