[css-scroll-snap] Fix more markup.

Author: tabatkins

css-scroll-snap/Overview.bs

@@ -436,9 +436,9 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-align}
 
 	<pre class="propdef">
 	Name: scroll-snap-align
-	Value: [ none | edges | <alignment> ] {1,2} |
-         [ block | inline]  [ none | edges | <alignment> ] |
-         point <alignment>{1,2}
+	Value: [ none | edges | <<alignment>> ] {1,2} |
+         [ block | inline]  [ none | edges | <<alignment>> ] |
+         point <<alignment>>{1,2}
 	Initial: none
 	Applies to: all elements
 	Inherited: no
@@ -460,7 +460,7 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-align}
 		<dfn for=scroll-snap-align><<alignment>></dfn> = center | [ start | end ] <<percentage>>?
 	</pre>
 
-	Issue: This is a subset of the L4 <<position> syntax
+	Issue: This is a subset of the L4 <<position>> syntax
 	that works within the constraint of an axis.
 	It also aligns with the <<self-position>> syntax from [[CSS-ALIGN-3]] (see e.g. 'align-self').
 	We could simplify to ''center | start | end'' by dropping <<percentage>>
@@ -561,7 +561,7 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-align}
 	and no <a>scroll axis keyword</a> is specified, then
 	the <<alignment>> value
 	applies to the scrollable axis of the affected <a>scroll container</a>.
-	If both axes are scrollable 
+	If both axes are scrollable
 	(i.e. both 'overflow-x' and 'overflow-y' are either ''overflow/scroll'' or ''overflow/auto''),
 	then it applies to the block axis of the affected <a>scroll container</a>
 	(as determined by the <a>scroll container</a>’s <a>writing mode</a>).
@@ -597,7 +597,7 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-align}
 		so are consistent with that syntax.
 		We chose to use this simpler syntax without lengths
 		because the 'scroll-snap-area' concept already provides length offsets--
-		but does so in a smarter way, that degrades better on small screens 
+		but does so in a smarter way, that degrades better on small screens
 		(see above) because it provides more information (a box, rather than a point) to the UA.
 		We could have also added lengths here,
 		but it would provide multiple ways to do the same thing,