lesson-block h3 glossary-terms don't have a close button

[AditiBhandari]

Haven't seen this issue in any of the other lessons I checked, and the lesson-block p glossary-terms do have close buttons.

[JoeGermuska]

Interesting... although arguably, there just shouldn't be glossary terms in display-oriented blocks like H3 tags. But I defer to @emilywithrow and @zachwise on content best-practices.