Replace example screenshot image with SVG version for Example 22 (w3c#1035)

* Replace example screenshot image with SVG version for Example 22

* [css-grid] Replace example screenshot image with SVG version for Example 22 (fix space conversion issue)

Author: Chen Hui Jing

css-grid/Overview.bs

@@ -2000,7 +2000,7 @@ Explicit Grid Shorthand: the 'grid-template' property</h3>
 				and creates the following grid:
 
 				<figure>
-					<object data="images/grid-shorthand.jpg" type="image/jpeg">
+					<object data="images/grid-shorthand.svg" type="image/svg+xml">
 						<ul>
 							<li>Three columns, sized ''auto'', ''1fr'', and ''auto'', respectively
 							<li>Two rows sized as ''auto'' and ''1fr'', respectively.