print directory node info

docs/onion-message-channels.md

@@ -153,7 +153,7 @@ who would like to help by running a directory node. You can ignore it if that do
 This requires a long running bot. It should be on a server you can keep running permanently, so perhaps a VPS,
 but in any case, very high uptime. For reliability it also makes sense to configure to run as a systemd service.
 
-The currently suggested way to run a directory node is to use the script found [here](https://github.com/JoinMarket-Org/custom-scripts/blob/0eda6154265e012b907c43e2ecdacb895aa9e3ab/start-dn.py); you can place it in your `joinmarket-clientserver/scripts` directory and run it *without* arguments, but with one option flag: `--datadir=/your/chosen/datadir` (as you'll see below).
+The currently suggested way to run a directory node is to use the script found [here](https://github.com/JoinMarket-Org/custom-scripts/blob/0eda6154265e012b907c43e2ecdacb895aa9e3ab/start-dn.py); you can place it in your `joinmarket-clientserver/scripts` directory and run it with the option flag: `--datadir=/your/chosen/datadir` (as you'll see below).
 
 This slightly unobvious approach is based on the following ideas: we run a Joinmarket script, with a Joinmarket python virtualenv, so that we are able to parse messages; this means that the directory node *can* be a bot, e.g. a maker bot, but need not be - and here it is basically a "crippled" maker bot that cannot do anything. This 'crippling' is actually very useful because (a) we use the `no-blockchain` argument (it is forced in-code; you don't need to set it) so we don't need a running Bitcoin node (of whatever flavour), and (b) we don't need a wallet either.
 

jmdaemon/jmdaemon/onionmc.py

@@ -1169,11 +1169,13 @@ def process_handshake(self, peerid: str, message: str,
                 accepted = handshake_json["accepted"]
                 nick = handshake_json["nick"]
                 net = handshake_json["network"]
+                motd = handshake_json["motd"]
                 assert isinstance(proto_max, int)
                 assert isinstance(proto_min, int)
                 assert isinstance(features, dict)
                 assert isinstance(nick, str)
                 assert isinstance(net, str)
+                assert isinstance(motd, str)
             except Exception as e:
                 log.warn("Invalid handshake message from: {},"
                 " exception: {}, message: {},ignoring".format(
@@ -1200,6 +1202,8 @@ def process_handshake(self, peerid: str, message: str,
                 return
             # We received a valid, accepting dn-handshake. Update the peer.
             peer.update_status(PEER_STATUS_HANDSHAKED)
+            # Show the info for the directory to the user, with emphasis:
+            self.info_callback("\n\n" + motd + "\n\n")
             peer.set_nick(nick)
         else:
             # it means, we are receiving an initial handshake