docs: remove sync example from readme

Author: GunnarMorrigan

README.md

@@ -153,88 +153,6 @@ async fn main() {
 
 ```
 
-### Sync example:
-```rust
-use mqrstt::{
-    MqttClient,
-    ConnectOptions,
-    new_sync,
-    packets::{self, Packet},
-    EventHandler,
-    sync::NetworkStatus,
-};
-use std::net::TcpStream;
-use bytes::Bytes;
-
-pub struct PingPong {
-    pub client: MqttClient,
-}
-
-impl EventHandler for PingPong {
-    // Handlers only get INCOMING packets. This can change later.
-    fn handle(&mut self, event: packets::Packet) {
-        match event {
-            Packet::Publish(p) => {
-                if let Ok(payload) = String::from_utf8(p.payload.to_vec()) {
-                    if payload.to_lowercase().contains("ping") {
-                        self.client
-                            .publish_blocking(
-                                p.topic.clone(),
-                                p.qos,
-                                p.retain,
-                                Bytes::from_static(b"pong"),
-                            ).unwrap();
-                        println!("Received Ping, Send pong!");
-                    }
-                }
-            },
-            Packet::ConnAck(_) => { println!("Connected!") },
-            _ => (),
-        }
-    }
-}
-
-
-let mut client_id: String = "SyncTcpPingReqTestExample".to_string();
-let options = ConnectOptions::new(client_id);
-
-let address = "broker.emqx.io";
-let port = 1883;
-
-let (mut network, client) = new_sync(options);
-
-// IMPORTANT: Set nonblocking to true! No progression will be made when stream reads block!
-let stream = TcpStream::connect((address, port)).unwrap();
-stream.set_nonblocking(true).unwrap();
-
-let mut pingpong = PingPong {
-    client: client.clone(),
-};
-
-network.connect(stream, &mut pingpong).unwrap();
-
-let res_join_handle = std::thread::spawn(move ||
-    loop {
-        match network.poll(&mut pingpong) {
-            Ok(NetworkStatus::ActivePending) => {
-                std::thread::sleep(std::time::Duration::from_millis(100));
-            },
-            Ok(NetworkStatus::ActiveReady) => {
-                std::thread::sleep(std::time::Duration::from_millis(100));
-            },
-            otherwise => return otherwise,
-        }
-    }
-);
-
-std::thread::sleep(std::time::Duration::from_secs(30));
-client.disconnect_blocking().unwrap();
-let join_res = res_join_handle.join();
-assert!(join_res.is_ok());
-let res = join_res.unwrap();
-assert!(res.is_ok());
-```
-
 ## FAQ
   - Not much gets frequently asked, so please do! :)
   - Open to feature requests