[css-typed-om] Fix return type of example (w3c#835)

jiayihu · tabatkins · commit a6008c4c2503 · 2018-11-27T11:39:08.000-08:00
diff --git a/css-typed-om/README.md b/css-typed-om/README.md
@@ -22,7 +22,7 @@ We get them of `StylePropertyMaps` on elements.
 
 To get the specified height from an element we would use the following JS:
 ```
-element.attributeStyleMap.get('height'); // returns a string
+element.attributeStyleMap.get('height'); // returns a CSSUnitValue
 ```
 
 Similarly to get the computed value of a CSS property we would do the following: 
