[css-line-grid] fix baseline links

Author: astearns

css-line-grid/Overview.html

@@ -408,11 +408,14 @@ <h3 class="heading settled" data-level=3.1 id=line-snap><span class=secno>3.1 </
 		<dd>The dominant baseline snaps with the matching baseline on the
 		line grid applying to the element.
 	<dt><dfn class=css data-dfn-for=line-snap data-dfn-type=value data-export="" id=valdef-line-snap-contain>contain<a class=self-link href=#valdef-line-snap-contain></a></dfn>
-		<dd>Two baselines are used to align the line box: the line box is
-		snapped so that its central baseline (halfway between the
-		text-over and text-under baselines) is centered between
-		one of the line grid’s text-over baselines and a subsequent
-		(but not necessarily consecutive) text-under baseline.
+		<dd>
+			Two baselines are used to align the line box: 
+			the line box is snapped 
+			so that its <a href=http://dev.w3.org/csswg/css-inline/#central>central</a> baseline 
+			is centered between one 
+			of the line grid’s <a href=http://dev.w3.org/csswg/css-inline/#text-over-edge>text-over-edge</a> baselines 
+			and a subsequent (but not necessarily consecutive) 
+			<a href=http://dev.w3.org/csswg/css-inline/#text-under-edge>text-under-edge</a> baseline.
 	</dl>
 
 <p>In some cases lines of equal line height

css-line-grid/Overview.src.html

@@ -310,11 +310,14 @@ <h3 id='line-snap'>
 		<dd>The dominant baseline snaps with the matching baseline on the
 		line grid applying to the element.
 	<dt><dfn>contain</dfn>
-		<dd>Two baselines are used to align the line box: the line box is
-		snapped so that its central baseline (halfway between the
-		text-over and text-under baselines) is centered between
-		one of the line grid's text-over baselines and a subsequent
-		(but not necessarily consecutive) text-under baseline.
+		<dd>
+			Two baselines are used to align the line box: 
+			the line box is snapped 
+			so that its <a href="http://dev.w3.org/csswg/css-inline/#central">central</a> baseline 
+			is centered between one 
+			of the line grid's <a href="http://dev.w3.org/csswg/css-inline/#text-over-edge">text-over-edge</a> baselines 
+			and a subsequent (but not necessarily consecutive) 
+			<a href="http://dev.w3.org/csswg/css-inline/#text-under-edge">text-under-edge</a> baseline.
 	</dl>
 
 	In some cases lines of equal line height