docs(typography): missing punctuation (twbs#31505)

site/content/docs/5.0/content/typography.md

@@ -145,7 +145,7 @@ Styling for common inline HTML5 elements.
 <p><del>This line of text is meant to be treated as deleted text.</del></p>
 <p><s>This line of text is meant to be treated as no longer accurate.</s></p>
 <p><ins>This line of text is meant to be treated as an addition to the document.</ins></p>
-<p><u>This line of text will render as underlined</u></p>
+<p><u>This line of text will render as underlined.</u></p>
 <p><small>This line of text is meant to be treated as fine print.</small></p>
 <p><strong>This line rendered as bold text.</strong></p>
 <p><em>This line rendered as italicized text.</em></p>