Improve or re-phrase "Link types to add language icons."

Spin-off from #310859: Various string issues:

[...], do you have any suggestion for a better (or perhaps re-)phrasing of "Link types to add language icons." - the #description for the "Add language icons" fieldset. Perhaps just appending a "to" would be enough, but that sounds a bit clumsy to me. "Link types for adding language icons to."? :/