Multichoice for the arg function

[BeSpunky]

I wrapped the arg function to allow multi-selection.
Just replace arg with multiArg and you're good to go. ✨😊
Provide a 3rd argument to customize item templates.

See code here

multiArg.mp4

Enter: Toggles Selection
Ctrl+Enter: Submits the results

Known issues:

• When the list is longer than the window, list jumps occur. See defaultValue doesn't scroll to choice if not visible #1248
• The input parameter passed into the choice factory function (2nd argument of arg) is always '' and doesn't reflect user input.
• List is filtered, but the default template doesn't highlight fuzzy search matches like the original one.

Enjoy 🥂