Fix typos

Author: schenney-chromium

css-pseudo-4/Overview.bs

@@ -939,7 +939,7 @@ Cascading and Per-Element Highlight Styles</h3>
   css/css-pseudo/cascade-highlight-002.html
   </wpt>
 
-  The following examples demonstrates the inheritaqnce of [=custom properties=].
+  The following example demonstrates the inheritance of [=custom properties=].
 
   <div class="example">
     For example, if an author specified