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>