Update 2.2. Manage contacts

Change-Id: I7eb74e6f2b8b57923ce9c5dfa30e60d351b105eb

technical/2.2.-Manage-contacts.md

@@ -10,14 +10,16 @@ The presence is pretty simple to announce on the DHT. In fact, it's just a value
 /**
  * Device announcement stored on DHT.
  */
-struct RingAccount::DeviceAnnouncement : public dht::SignedValue<DeviceAnnouncement>
+struct DeviceAnnouncement : public dht::SignedValue<DeviceAnnouncement>
 {
 private:
     using BaseClass = dht::SignedValue<DeviceAnnouncement>;
+
 public:
     static const constexpr dht::ValueType& TYPE = dht::ValueType::USER_DATA;
     dht::InfoHash dev;
-    MSGPACK_DEFINE_MAP(dev);
+    std::shared_ptr<dht::crypto::PublicKey> pk;
+    MSGPACK_DEFINE_MAP(dev, pk)
 };
 ```