Automatically generate Samples wiki page from README files.

Reviewed in http://codereview.appspot.com/5900069/.

Index: samples-index.py
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new file mode 100644
diff --git a/samples/tasks_appengine/README b/samples/tasks_appengine/README
index 56da2e8..6888c35 100644
--- a/samples/tasks_appengine/README
+++ b/samples/tasks_appengine/README
@@ -1,2 +1,5 @@
 Sample code for Getting Started with Tasks API on App Engine article.
 http://code.google.com/appengine/articles/python/getting_started_with_tasks_api.html
+
+api: tasks
+keywords: appengine