Updated Whisper Push Notifications (markdown)

Whisper-Push-Notifications.md

@@ -50,7 +50,33 @@ Original workflow for discovery mechanism was introduced in:
 
 [![image](https://cloud.githubusercontent.com/assets/188194/24608168/19317cdc-187e-11e7-995e-2adadc17a91c.png)](https://cloud.githubusercontent.com/assets/188194/24608168/19317cdc-187e-11e7-995e-2adadc17a91c.png)
 
-Let's give a concrete code example:
+Everything starts with `Device A` willing to register with some Notification Service Provider, for that discovery request needs to be sent:
+
+```js
+var discoverServerTopic = '0x268302f3'; // DISCOVER_NOTIFICATION_SERVER
+var sendDiscoveryRequest = function (identity) {
+    // notification server discovery request is a signed (sent from us) broadcast,
+    // encrypted with Notification Protocol Symmetric Key (which is publicly known)
+    var err = web3.shh.post({
+        from: identity,
+        topics: [discoverServerTopic],
+        ttl: 20,
+        keyname: 'NOTIFICATION_PROTOCOL_KEY'
+    });
+    if (err !== null) {
+        console.log("message NOT sent")
+    } else {
+        console.log("message sent OK")
+    }
+};
+
+var identity = web3.shh.newIdentity();
+sendDiscoveryRequest(identity);
+```
+Once that request is sent all capable wnodes respond back, so we need to watch for their responses, and select one provider (generally FIFO):
+
+```js
+```
 
 # Sharing the key