Editorial: fix typo

Closes whatwg#2790.

source

@@ -9683,8 +9683,7 @@ partial interface <dfn id="document" data-lt="">Document</dfn> {
    <p>Because HTML conveys <em>meaning</em>, rather than presentation, the same
    page can also be used by a small browser on a mobile phone, without any change to the page.
    Instead of headings being in large letters as on the desktop, for example, the browser on the
-   mobile phone might use the same size text for the whole the page, but with the headings in
-   bold.</p>
+   mobile phone might use the same size text for the whole page, but with the headings in bold.</p>
 
    <p>But it goes further than just differences in screen size: the same page could equally be used
    by a blind user using a browser based around speech synthesis, which instead of displaying the