feat: custom number formatter function

[ankush]

You can now pass numberFormatter function in axisOptions to customize the behavior of number shortening. This is required in countries where K/M/B/T is not the standard way of shortening large numbers. E.g. India has thousands, lakh (1e5), crore (1e7).

The interface for this function is pretty simple

(value) => {
    // format value
    return value
};

Outcome