Applies a vertical margin between the child elements.
<.stack>
<div>some block</div>
<div>some other block</div>
</.stack>
By default, the margin is only applied to the direct children of the
component. To apply a vertical margin on children at any nesting level, set
the recursive
attribute.
<.stack recursive>
<div>
<div>some nested block</div>
<div>another nested block</div>
</div>
<div>some other block</div>
</.stack>