Buttons Block: Add full-width button style

[iamtakashi]

It'd be nice to allow a button to be full-width of a parent.

For example, full-width buttons are pretty common in a pattern like a pricing table.

Full-width buttons can be seen in forms too, and it could be useful to add a block style for it.

[alaczek]

Yes, I agree. I'm wondering though if it wouldn't be more useful to be able to set the width of the button, which would cover full-width buttons too. This is the design I had in mind:

[mtias]

cc @apeatling for thoughts. It seems like some predefined percentages could be useful as well — 50%, 25% etc. Or it could be a count of how many buttons per row.

[apeatling]

I like the idea of setting percentages, and using flexbox so the columns sort themselves out based on width.

[iamtakashi]

The awesome work from @stacimc made this reality, thank you!