index Change vertical_text heading to writing_mode

index.html

@@ -82,8 +82,8 @@ <h2>Introduction</h2>
 <h2>Text direction</h2>
 
 
-<section id="vertical_text">
-<h3>Vertical text</h3>
+<section id="writing_mode">
+<h3>Writing mode</h3>
 
 <p>When dealing with vertical lines of text, it's common for content authors to want to mix short horizontal runs of text, such as 2-digit numbers, in a vertical column (tate chu yoko). It's also important to provide appropriate support for text in scripts that are normally only horizontal. Also, there are often special requirements related to the orientation of characters within vertical text.</p>