[css-values] typo

Author: tabatkins

css-values/Overview.bs

@@ -1013,7 +1013,7 @@ Absolute lengths: the ''cm'', ''mm'', ''q'', ''in'', ''pt'', ''pc'', ''px'' unit
 	results in a reference pixel of 1.3 mm.
 
 	<figure>
-		<img src="pixel1.png"
+		<img src="images/pixel1.png"
 		        alt="This diagram illustrates how the definition of a pixel
 		             depends on the users distance from the viewing surface
 		             (paper or screen).
@@ -1034,7 +1034,7 @@ Absolute lengths: the ''cm'', ''mm'', ''q'', ''in'', ''pt'', ''pc'', ''px'' unit
 	(such as a printer).
 
 	<figure>
-		<img src="pixel2.png"
+		<img src="images/pixel2.png"
 		        alt='This diagram illustrates the relationship between the
 		             reference pixel and device pixels (called "dots" below).
 		             The image depicts a high resolution (large dot density)