Fix minor typo

Author: Flavsm

css-display-3/Overview.bs

@@ -81,7 +81,7 @@ Introduction</h2>
 	and renders it onto a <a href="https://www.w3.org/TR/CSS2/intro.html#canvas">canvas</a>
 	such as your screen, a piece of paper, or an audio stream.
 	Although any such source document can be rendered with CSS,
-	the most commonly used type is the the DOM. [[DOM]]
+	the most commonly used type is the DOM. [[DOM]]
 	(Some of these more complex tree types might have additional types of nodes,
 	such as the comment nodes in the DOM.
 	For the purposes of CSS,