Themeable by Chakra theme

[VaZark]

We used the date picker on multiple pages. So we created a component that just added styling and re-exported it to have a consistent design.

It would be cool to be able to theme it with Chakra's extendTheme as a multipart theme

[aboveyunhai]

@VaZark To be honest, I didn't consider the theme when created this lib because the inner structure keeps changing here and there at that time and theme is barely usable for my use case.
I'm not sure how to do it nowadays. If you have an idea how to do it and limit the theme scope inside this datapicker only (so the theme wouldn't override other people's theme accidentally), feel free to create a pr. Even the PR is buggy, as long as it semi-support the basic theme that you would expect and align with the basic Chakra theme style, then I think I can help you finish the rest.