Better organization of time-based pseudos

Author: fantasai

selectors4/Overview.html

@@ -1979,13 +1979,17 @@ <h3 id=active-pseudo><span class=secno>8.3. </span> The input focus
   <h2 id=time-pseudo><span class=secno>9. </span> Time-linear Presentation
    Pseudo-classes</h2>
 
+  <p>These pseudo-classes classify elements with respect to an active
+   position in a time-dimensional canvas, such as during speech rendering of
+   an HTML document.
+
   <h3 id=current-pseudo><span class=secno>9.1. </span> The current-element
    pseudo-class <code>:current</code></h3>
 
   <p>The <code>:current</code> pseudo-class represents the innermost element,
-   or ancestor of an element, that is currently being displayed in a
-   time-dimensional canvas, such as during speech rendering of an HTML
-   document. Its alternate form <code>:current()</code>, like
+   or ancestor of an element, that is currently being displayed.
+
+  <p>Its alternate form <code>:current()</code>, like
    <code>:matches()</code>, takes a list of compound selectors as its
    argument: it represents the <code>:current</code> element that matches the
    argument or, if that does not match, the innermost ancestor of the

selectors4/Overview.src.html

@@ -1461,14 +1461,17 @@ <h3 id="active-pseudo">
 <h2 id="time-pseudo">
 Time-linear Presentation Pseudo-classes</h2>
 
+  <p>These pseudo-classes classify elements with respect to an active
+    position in a time-dimensional canvas,
+    such as during speech rendering of an HTML document.
+
 <h3 id="current-pseudo">
 The current-element pseudo-class <code>:current</code></h3>
 
   <p>The <code>:current</code> pseudo-class represents the innermost
-    element, or ancestor of an element, that is currently being displayed
-    in a time-dimensional canvas, such as during speech rendering of an
-    HTML document.
-    Its alternate form <code>:current()</code>, like <code>:matches()</code>,
+    element, or ancestor of an element, that is currently being displayed.
+
+  <p>Its alternate form <code>:current()</code>, like <code>:matches()</code>,
     takes a list of compound selectors as its argument: it represents the
     <code>:current</code> element that matches the argument or, if that does
     not match, the innermost ancestor of the <code>:current</code> element