Cryptstorage: fix confusing code example

src/jio.storage/cryptstorage.js

@@ -10,24 +10,29 @@
 (function (jIO, RSVP, DOMException, Blob, crypto, Uint8Array, ArrayBuffer) {
   "use strict";
 
+  /*
+  The cryptography system used by this storage is AES-GCM.
+  Here is an example of how to generate a key to the json format:
 
-  // you the cryptography system used by this storage is AES-GCM.
-  // here is an example of how to generate a key to the json format.
-
-  // var key,
-  //     jsonKey;
-  // crypto.subtle.generateKey({name: "AES-GCM",length: 256},
-  //                           (true), ["encrypt", "decrypt"])
-  // .then(function(res){key = res;});
-  //
-  // window.crypto.subtle.exportKey("jwk", key)
-  // .then(function(res){jsonKey = val})
-  //
-  //var storage = jIO.createJIO({type: "crypt", key: jsonKey,
-  //                             sub_storage: {...}});
-
-  // find more informations about this cryptography system on
-  // https://github.com/diafygi/webcrypto-examples#aes-gcm
+  return new RSVP.Queue()
+    .push(function () {
+      return crypto.subtle.generateKey({name: "AES-GCM", length: 256},
+                                       true, ["encrypt", "decrypt"]);
+    })
+    .push(function (key) {
+      return crypto.subtle.exportKey("jwk", key);
+    })
+    .push(function (json_key) {
+      var jio = jIO.createJIO({
+        type: "crypt",
+        key: json_key,
+        sub_storage: {storage_definition}
+      });
+    });
+
+  Find more informations about this cryptography system on
+  https://github.com/diafygi/webcrypto-examples#aes-gcm
+  */
 
   /**
    * The JIO Cryptography Storage extension