[css-grid] Typo fix.

Author: SimonSapin

css-grid/Overview.src.html

@@ -376,7 +376,7 @@ <h2 id='grid-concepts'>
 		into which <a>grid items</a> (representing the <a>grid container</a>’s content) can be placed.
 		There are two sets of <a>grid lines</a>:
 		one set defining <dfn export title="grid column | column">columns</dfn>
-		that run along the <a href="http://www.w3.org/TR/css3-writing-modes/#block-axis">block axis</a> (the <dfn export>column axis</dfn>,
+		that run along the <a href="http://www.w3.org/TR/css3-writing-modes/#block-axis">block axis</a> (the <dfn export>column axis</dfn>),
 		and an orthogonal set defining <dfn export title="grid row | row">rows</dfn>
 		along the <a href="http://www.w3.org/TR/css3-writing-modes/#inline-axis">inline axis</a> (the <dfn export>row axis</dfn>).
 		[[!CSS3-WRITING-MODES]]