Improve WebSocket and Storage docs.

lib/html/doc/interface/Storage.dartdoc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// @domName Storage
+/**
+ * The type used by the
+ * [Window.localStorage] and [Window.sessionStorage] properties.
+ * Storage is implemented as a Map<String, String>.
+ *
+ * To store and get values, use Dart's built-in map syntax:
+ *
+ *     window.localStorage['key1'] = 'val1';
+ *     window.localStorage['key2'] = 'val2';
+ *     window.localStorage['key3'] = 'val3';
+ *     assert(window.localStorage['key3'] == 'val3');
+ * 
+ * You can use [Map](http://api.dartlang.org/dart_core/Map.html) APIs
+ * such as containsValue(), clear(), and length:
+ *
+ *     assert(window.localStorage.containsValue('does not exist') == false);
+ *     window.localStorage.clear();
+ *     assert(window.localStorage.length == 0);
+ *
+ * For more examples of using this API, see
+ * [localstorage_test.dart](http://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/tests/html/localstorage_test.dart).
+ * For details on using the Map API, see the
+ * [Maps](http://www.dartlang.org/docs/library-tour/#maps-aka-dictionaries-or-hashes)
+ * section of the library tour.
+ *
+ */
 interface Storage extends Map<String, String> {
 
   /** @domName Storage.length */
   final int $dom_length;
 
   /** @domName Storage.clear */
   void $dom_clear();
 
   /** @domName Storage.getItem */
   String $dom_getItem(String key);
 
   /** @domName Storage.key */
   String $dom_key(int index);
 
   /** @domName Storage.removeItem */
   void $dom_removeItem(String key);
 
   /** @domName Storage.setItem */
   void $dom_setItem(String key, String data);
 
 }