added a 'help' method

README.md

@@ -49,6 +49,7 @@ eclair.bitcoind.rpcpassword (default: bar)
   addhtlc     | channel_id, amount, rhash, locktime | sends an htlc
   fulfillhtlc | channel_id, r                       | fulfills an htlc
   close       | channel_id                          | closes a channel
+  help        |                                     | displays available methods
 
 ## Status
 - [X] Network

eclair-demo/src/main/scala/fr/acinq/eclair/api/Service.scala

@@ -81,6 +81,14 @@ trait Service extends HttpService with Logging {
                 sendCommand(channel, CMD_SEND_HTLC_FULFILL(BinaryData(r)))
               case JsonRPCBody(_, _, "close", JString(channel) :: Nil) =>
                 sendCommand(channel, CMD_CLOSE(Globals.closing_fee))
+              case JsonRPCBody(_, _, "help", _) =>
+                Future.successful(List(
+                  "connect (host, port, anchor_amount): opens a channel with another eclair or lightningd instance",
+                  "list: lists existing channels",
+                  "addhtlc (channel_id, amount, rhash, locktime): sends an htlc",
+                  "fulfillhtlc (channel_id, r): fulfills an htlc",
+                  "close (channel_id): closes a channel",
+                  "help: displays this message"))
               case _ => Future.failed(new RuntimeException("method not found"))
             }