Multi-select 'finished' UI element

[shaneporter]

Currently, when selecting items for the multi-select, there is no way (other than adding a 'submit' button to the form) to trigger a 'submission' of the data.

An alternative is to add a small UI element (perhaps a small button) that is clicked when the user has finished making their selections and wish for the form to be submitted.

This will default to not being shown.