Added _index.html and screenshots to all samples.

Bug 15814554

Change-Id: Icdb08c5cc39f97c88674e4177b88b47adce59127

samples/wearable/Flashlight/_index.html

@@ -0,0 +1,12 @@
+<p><b>About:</b> Wearable activity that uses your wearable screen as a flashlight. There is also
+a party-mode option, if you want to make things interesting.</p>
+<p><b>How to run:</b> Install the Wearable APK on the wearable, go to the voice menu (either by
+saying "OK Google" or tapping the home screen) and select the "Start..." option. Then, select
+"Flashlight" from the submenu.</p>
+<p><b>Screenshots:</b>
+    <figure>
+        <img src="screenshots/flashlight.png" alt="Flashlight" width="140" height="140">
+        <img src="screenshots/party_mode.gif" alt="Party mode!" width="140" height="140">
+        <figcaption>Plain flashlight, followed by party-mode.</figcaption>
+    </figure>
+</p>