[css-grid] Fix typo. Fixes w3c#1602.

Author: fantasai

css-grid/Overview.bs

@@ -646,7 +646,7 @@ Grid Tracks and Cells</h3>
 Grid Areas</h3>
 
 	A <dfn export>grid area</dfn> is the logical space used to lay out one or more <a>grid items</a>.
-	A <a>grid area</a> consists of one or more adjecent <a>grid cells</a>.
+	A <a>grid area</a> consists of one or more adjacent <a>grid cells</a>.
 	It is bound by four <a>grid lines</a>, one on each side of the <a>grid area</a>,
 	and participates in the sizing of the <a>grid tracks</a> it intersects.
 	A <a>grid area</a> can be named explicitly using the 'grid-template-areas' property of the <a>grid container</a>,