[css-grid] Break 'grid' across lines for more readability.

Author: tabatkins

css-grid/Overview.bs

@@ -2117,7 +2117,10 @@ Grid Definition Shorthand: the 'grid' property</h2>
 
 	<pre class='propdef'>
 	Name: grid
-	Value: none | subgrid | <nobr>[ <<'grid-template-rows'>> / <<'grid-template-columns'>> ]</nobr> | <nobr>[ <<line-names>>? <<string>> <<track-size>>? <<line-names>>? ]+ [ / <<track-list>> ]?</nobr> | <nobr>[ <<'grid-auto-flow'>> [ <<'grid-auto-rows'>> [ / <<'grid-auto-columns'>> ]? ]? ]</nobr>
+	Value: none | subgrid |
+	Value: <nobr>[ <<'grid-template-rows'>> / <<'grid-template-columns'>> ]</nobr> |
+	Value: <nobr>[ <<line-names>>? <<string>> <<track-size>>? <<line-names>>? ]+ [ / <<track-list>> ]?</nobr> |
+	Value: <nobr>[ <<'grid-auto-flow'>> [ <<'grid-auto-rows'>> [ / <<'grid-auto-columns'>> ]? ]? ]</nobr>
 	Initial: see individual properties
 	Applies to: <a>grid containers</a>
 	Inherited: see individual properties