Docs: Adding links to headset spec and host mode article

Bug: 18149988
Change-Id: I564598f67ba6b3733b48b87f42a842d032ac08ca
diff --git a/src/accessories/index.jd b/src/accessories/index.jd
index 1157d5d..4caaeff 100644
--- a/src/accessories/index.jd
+++ b/src/accessories/index.jd
@@ -22,21 +22,26 @@
 Android-powered devices.
 </p>
 
-<div class="layout-content-row">  
+<div class="layout-content-row">
 
   <div class="layout-content-col span-6">
-	<h4 id="audio-accessories">Audio Accessories</h4>
-	<p>Android supports local on-device audio and remote off-device audio
-        over a wired 3.5 mm headset jack, USB connection, or Bluetooth.</p>
-	<p><a href="{@docRoot}accessories/audio.html">&raquo; Audio Accessories</a></p>
+        <h4 id="audio-accessories">Audio Accessories</h4>
+        <p>Android supports local on-device audio and remote off-device audio
+        over a wired 3.5 mm headset jack, USB connection, or Bluetooth.
+        Developers should see the <a
+        href="{@docRoot}accessories/headset-spec.html">wired audio headset
+        specification</a>, while users may learn how to <a
+        href="https://support.google.com/nexus/answer/6127700">record and play
+        back audio using USB host mode</a>.</p>
+        <p><a href="{@docRoot}accessories/audio.html">&raquo; Audio Accessories</a></p>
   </div>
-    
+
   <div class="layout-content-col span-6">
-	<h4 id="custom-accessories">Custom Accessories</h4>
-	<p>What do you want to connect to your Android device? Alarm clock? Keyboard? Thermostat? Robot?
-	Learn how to connect existing equipment or your own unique hardware to
+        <h4 id="custom-accessories">Custom Accessories</h4>
+        <p>What do you want to connect to your Android device? Alarm clock? Keyboard? Thermostat? Robot?
+        Learn how to connect existing equipment or your own unique hardware to
         Android using the Android Open Accessory Protocol.</p>
-	<p><a href="{@docRoot}accessories/custom.html">&raquo; Custom Accessories</a></p>
+        <p><a href="{@docRoot}accessories/custom.html">&raquo; Custom Accessories</a></p>
  </div>
 
 </div>