Swap
With Swap="true" the list no longer sorts. Instead, the item you drag over is highlighted, and
on drop the dragged item trades places with it. Swapping works inside a single list and between lists that
share a group. This mirrors the SortableJS
Swap plugin.
Single list
Item 1
Item 2
Item 3
Item 4
Item 5
Item 6
Order: Item 1, Item 2, Item 3, Item 4, Item 5, Item 6
Across two lists
Item 1
Item 2
Item 3
Item 4
Item A
Item B
Item C
Item D
Left: Item 1, Item 2, Item 3, Item 4
Right: Item A, Item B, Item C, Item D