How do I group and add space between checkboxes? I need to group the checkboxes and put some spacing between each group.
They need to look like this:

item1
item2

item3
item4


I can easily add an additional field to the options array specifying which group each item belongs to but I how do I render them this way?
I imagine I would have to do this by adding classes. But how do I do that?
You can normally do this already without any extra effort.

Each option should have a class assigned to it that you can target in your CSS.

You can then apply any spacing you like there.