Add CLI args for broker address and port

README.md

@@ -12,9 +12,14 @@ A simple Rust application that publishes messages to an MQTT broker.
 ## Usage
 
 ```bash
-cargo run
+cargo run -- --broker 192.168.1.100 --port 1883
 ```
 
+### Arguments
+
+- `broker`: MQTT broker address (default: `localhost`)
+- `port`: MQTT broker port (default: `1883`)
+
 ## Configuration
 
 Edit `src/main.rs` to customize: