Doc change: minor edits to support easier extraction of document summaries.

Change-Id: I1a15a1d233464d6c8d35a741c54932412dea28ee
diff --git a/docs/html/design/index.jd b/docs/html/design/index.jd
index 8f73d9c..9ba32dd 100644
--- a/docs/html/design/index.jd
+++ b/docs/html/design/index.jd
@@ -22,7 +22,8 @@
 
 <div id="landing-graphic-container">
   <div id="text-overlay">
-    Welcome to <strong>Android Design</strong>, your place for learning how to design exceptional Android apps.
+    <span itemprop="description">Welcome to <strong>Android Design</strong>, your place for
+    learning how to design exceptional Android apps.</span>
     <br><br>
     Want to know what <strong>Android 4.4 KitKat</strong> has for designers? See <a href="{@docRoot}design/patterns/new.html">New in Android</a>.<br><br>
     <a href="/design/get-started/creative-vision.html" class="landing-page-link">Creative Vision</a>