[css-page-floats-3][editorial] Gloss out-of-flow jargon (#13032)

Author: cvrebert

css-page-floats-3/Overview.bs

@@ -994,7 +994,7 @@ Differences between inline floats and absolutely positioned elements</h3>
   <em>This section is not normative.</em>
 
   <p>
-    Inline floats and absolutely positioned elements are both out-of-flow elements.
+    Inline floats and absolutely positioned elements are both <a>out-of-flow</a> elements.
     Absolutely positioned elements that are also exclusions can imitate many of
     the features of floats.