f docs + TODO

Author: valentinewallace

lightning/src/routing/onion_message.rs

@@ -34,7 +34,8 @@ use prelude::*;
 
 /// Finds a route from us to the given `destination` node.
 /// If we have private channels, it may be useful to fill in `first_hops` with the results from
-/// [`ChannelManager::list_usable_channels`].
+/// [`ChannelManager::list_usable_channels`]. If `first_hops` is not filled in, connected peers
+/// without public channels will not be forwarded over.
 ///
 /// [`ChannelManager::list_usable_channels`]: crate::ln::channelmanager::ChannelManager::list_usable_channels
 pub fn find_path<L: Deref, GL: Deref>(