Add clarifying comment for duplicate serverName parameter

Co-authored-by: RobotHanzo <36107150+RobotHanzo@users.noreply.github.com>

Author: Copilot

velocity/src/main/java/com/convallyria/forcepack/velocity/listener/ServerRegistrationListener.java

@@ -39,6 +39,7 @@ public void onServerRegistered(ServerRegisteredEvent event) {
 
                 configs.forEach((id, config) -> {
                     if (config == null) return;
+                    // serverName is used both as the config name and target server name
                     plugin.registerResourcePackForServer(config, id, serverName, "server", plugin.getConfig().getBoolean("verify-resource-packs"), serverName, null);
                 });
                 return;