made directory structure in html tutorial 5 match example files directory structure

Author: Helen Brockelbank

html/lesson5/tutorial.md

@@ -234,8 +234,8 @@ You can also set different properties for your backgrounds, by defining them in
 First let's set two background images, the first positioned on the right and the second on the left.
 
 ```
-background: url('assets/images/background-right.jpg') right top no-repeat,
-            url('assets/images/background-left.jpg') left no-repeat;
+background: url('background-right.jpg') right top no-repeat,
+            url('background-left.jpg') left no-repeat;
 ```
 
 By default, a background image repeats itself to fill in the container. We don't want that, that's where the **no-repeat** property we specified comes into place.