[css3-text] Clarify handling of letter-spacing at element boundaries again.

Author: fantasai

css-text-decor-3/Overview.src.html

@@ -472,7 +472,7 @@ <h3 id="text-decoration-skip-property">
     <dd>Skip this element if it is an atomic inline (such as an
       image or inline-block).</dd>
     <dt><dfn title="text-decoration-skip:spaces">''spaces''</dfn></dt>
-    <dd>Skip white space: this includes regular spaces (U+0020) and
+    <dd>Skip white space: this includes spaces (U+0020) and
       tabs (U+0009), as well as nbsp (U+00A0), ideographic space
       (U+3000), all fixed width spaces (such as U+2000&ndash;U+200A,
       U+202F and U+205F), and any adjacent letter-spacing or