getting-started.html: add <code> around mention of `placeholder`

getting-started.html

@@ -146,7 +146,7 @@ bootstrap/
     <p>Unofficially, Bootstrap should look and behave well enough in Chromium for Linux and Internet Explorer 7, though they are not officially supported.</p>
 
     <h3>Internet Explorer 8 and 9</h3>
-    <p>Internet Explorer 8 and 9 are also supported, however, please be aware that many CSS3 properties—e.g., rounded corners and shadows—are not supported by IE8. The placeholder attribute is also not supported in either of these versions.</p>
+    <p>Internet Explorer 8 and 9 are also supported, however, please be aware that many CSS3 properties—e.g., rounded corners and shadows—are not supported by IE8. The <code>placeholder</code> attribute is also not supported in either of these versions.</p>
     <p>In addition, <strong>Internet Explorer 8 requires the use of <a href="https://github.com/scottjehl/Respond">respond.js</a> to enable media query support.</strong></p>
 
     <h3>IE Compatibility modes</h3>