Expose the default props

[mrfullset]

#706

I've exposed shared folder which contains default definitions of format*. Unfortunately, I wasn't able to find default implementation for navigationLabel function.

[wojtekmaj]

I'm sorry, but it's a no from me. The reason is that this vastly expands the amount of "public" code that, when changed, would potentially create a breaking change and I would need to be much, much more careful about what I'm doing in these files. Moreover, without proper documentation, you're still pretty much on your own, so this change alone doesn't provide much value.

However, I'll consider moving certain parts of this code to a separate, public, documented package that I would be able to use in my packages, including React-Calendar - and so would you! Is that something that you would be happy with?