Adding support for custom header cells

Would it be possible to add support for custom rendering of the header cells as well?

Ideally I’d like to be able to have the capability to do something like this within the header cells: https://codesandbox.io/s/9m9qs

I imagine the easiest way to implement this would be an additional prop such as the following: drawHeaderCell?: (args) => boolean;

Otherwise, this library is perfect for my needs. Fantastic job.

[jassmith]

I’ll add a draw callback, will need to sit down and work out the details

[jassmith]

You would need to look in the 3.1.3 branch. The production storybook wont update until I merge 3.1.3 to the main branch.