Update router docs

Author: naumenkogs

lightning/src/ln/router.rs

@@ -1,7 +1,7 @@
 //! The top-level routing logic lives here.
 //!
-//! You probably want to create a Router and use that as your RoutingMessageHandler and then
-//! interrogate it to get routes for your own payments.
+//! Helps to create routes for your own payments based on the NetworkGraph,
+//! constructed from network messages which may come from different sources.
 
 use secp256k1::key::PublicKey;
 
@@ -155,13 +155,13 @@ struct DummyDirectionalChannelInfo {
 }
 
 impl Router {
-	/// Creates a new router with the given node_id to be used as the source for get_route()
+	/// Creates a new router
 	pub fn new(logger: Arc<Logger>) -> Self {
 		Router {
 			logger: logger.clone(),
 		}
 	}
-	/// Gets a route from us to the given target node.
+	/// Gets a route from us (as specified in the provided NetworkGraph) to the given target node.
 	///
 	/// Extra routing hops between known nodes and the target will be used if they are included in
 	/// last_hops.