Add ability to hide some labels while showing others

[tmthyjames]

Great library.

I want to be able to hide some labels and show others because if a certain value is dwarfed by other values to the point where their section of the funnel is only a few pixels in height, then their labels don't adjust and it looks cluttered.

Screenshot:

Notice the categories in the middle.

If this is already possible, I will be happy to close this ticket. If not, I'd be happy to give it a go.

[jakezatecky]

I have been considering adding an option to hide labels globally, specifically in consideration of #10 and #45, but did not plan for anything on a block-level.

I suppose this could be added, but I hesitate to add yet another index to the existing data structure array. I think it might be appropriate to allow for an object to be used in place of an array; that would make it cleaner to allow block-level customizations like hiding labels. I'll consider making that a feature that has backwards compatibility with the existing data structure.

In the interim, you might consider setting a minimum height, such that each block is guaranteed to have a height large enough to support the text:

const options = {
    block: {
        dynamicHeight: true,
        minHeight: 25,
    },
};