Current behavior:
When you press enter inside a definition list, a new list item of the same type is created.

Suggested behavior:
When you press enter

• inside a list item, it should be split as it is done currently
• at the end of a list item, an item of the other type should be created (which is the most common use of definition lists)
• in an empty list item, the list should be closed (like for bulleted/numbered lists).