ax(node): replace Send comment that restated the signature with a usage example

AX Principle 2: comments show HOW with real values, not WHAT the type
signature already says. "Send sends an encrypted message over the
connection." adds zero information.

Co-Authored-By: Charon <charon@lethean.io>

pkg/node/transport.go

@@ -818,7 +818,7 @@ func (t *Transport) removeConnection(pc *PeerConnection) {
 	pc.Close()
 }
 
-// Send sends an encrypted message over the connection.
+// if err := conn.Send(msg); err != nil { logging.Error("send failed", ...) }
 func (pc *PeerConnection) Send(msg *Message) error {
 	pc.writeMu.Lock()
 	defer pc.writeMu.Unlock()