Add intro to any Chrome app API that has nothing in place already.

chrome/common/extensions/docs/templates/articles/app_hardware.html

 <h1>Accessing Hardware Devices</h1>
 
 
 <p>
 This doc shows you how packaged apps can connect to USB devices
 and read from and write to a user's serial ports.
 See also the reference docs for the
-<a href="experimental.usb.html">USB API</a>
+<a href="usb.html">USB API</a>
 and the
 <a href="serial.html">Serial API</a>.
-The <a href="experimental.bluetooth.html">Bluetooth API</a> has just landed and
-we'll write more on this soon.
-We've included a link to an early sample below.
+The <a href="bluetooth.html">Bluetooth API</a> is also available
+(<a href="app_known_issues.html">known issues</a> still to be resolved);
+we've included a link to a bluetooth sample below.

[miket_OOO, 2012/11/28 19:21:22]

I think that as a rule, "Bluetooth" in prose should be capitalized.

[mkearney1, 2012/11/30 21:42:59]

Done.

 </p>
 
 <p class="note">
 <b>API Samples: </b>
 Want to play with the code?
 Check out the
 <a href="https://github.com/GoogleChrome/chrome-app-samples/tree/master/serial">serial</a>,
 <a href="https://github.com/GoogleChrome/chrome-app-samples/tree/master/servo">servo</a>,
 <a href="https://github.com/GoogleChrome/chrome-app-samples/tree/master/usb">usb</a>,
-and <a href="https://github.com/GoogleChrome/chrome-app-samples/tree/master/bluetooth-demo">bluetooth-demo</a> samples.
+and <a href="https://github.com/GoogleChrome/chrome-app-samples/tree/master/zephyr_hxm">bluetooth</a> samples.
 </p>
 
 <h2 id="usb">Accessing USB devices</h2>
 
 <p>
 You can use the USB API to send messages to any connected device.
 </p>
 
 <h3 id="manifest">Manifest requirement</h3>
 
@@ skipping 653 matching lines @@
 You can flush your serial device buffer by issuing the flush command on the API:
 </p>
 
 <pre>
 var flushSerial=function(str) {
   chrome.experimental.serial.flush(connectionInfo.connectionId, onFlush);
 }
 </pre>
 
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