Cannot add an item to a checkbox list at the desired location (only the end)

[tyeth]

I should be able to insert an item in the checkbox list (the last item of Python should be below arduino item).
The keyboard and mouse interactions around this are useless and do not allow such functionality.
Presumably only serially appended lists are tested/used by anyone.

[flavorjones]

@tyeth A pull request for this would be welcome.