Allow menu item descriptions to appear as the caption

Problem/Motivation

In Drupal core, menu items have a "Description" field which can be edited either in the menu or on the node edit page. I would like to be able to configure a mega menu to use the value of the description as the menu item's caption.

Proposed resolution

Add a configuration to use the value of the description as the menu item's caption if the caption is empty.

Remaining tasks

Implement.

User interface changes

Additional configuration.

API changes

None.

Data model changes

None.