Updated readme with information about how to enable peer-to-peer messaging.

Author: markspanbroek

Readme.md

@@ -3,9 +3,19 @@ Shhwift
 
 A client for the [Ethereum Whisper][1] communication protocol, written in Swift.
 
-Currently requires a running Ethereum node with Whisper enabled on the JSON-RPC interface. For instance, by running [Ethereum Go][2] with the following parameters:
+### Running an ethereum node
+
+Shhwift currently requires a running Ethereum node with Whisper enabled on the JSON-RPC interface. For instance, by running [Ethereum Go][2] with the following parameters:
 
     geth --shh --rpc --rpcapi "shh"
 
+### Enabling Peer-to-peer messaging
+
+The default Ethereum boot nodes currently do not run Whisper. This means that you won't be able to participate in the Whisper peer-to-peer network, unless you explicitly use a Whisper node as bootnode. 
+
+You can run such a bootnode yourself by running ``geth --shh`` and use the enode url that it prints upon startup as the bootnode argument for the other nodes:
+
+    geth --shh --rpc --rpcapi "shh" --bootnodes enode://<public key>@<ip address>:30303 
+
 [1]: https://github.com/ethereum/wiki/wiki/Whisper
-[2]: https://github.com/ethereum/go-ethereum 
+[2]: https://github.com/ethereum/go-ethereum