rust-sdk: add additinal example

sdk/rust/nym-sdk/examples/simple_but_manually_connect.rs

@@ -0,0 +1,27 @@
+use nym_sdk::mixnet;
+
+#[tokio::main]
+async fn main() {
+    logging::setup_logging();
+
+    // Create client builder, including ephemeral keys. The builder can be usable in the context
+    // where you don't want to connect just yet
+    let client = mixnet::ClientBuilder::new(None, None).unwrap();
+
+    // Now we connect to the mixnet, using ephemeral keys already created
+    let mut client = client.connect_to_mixnet().await.unwrap();
+
+    // Be able to get our client address
+    let our_address = client.nym_address();
+    println!("Our client nym address is: {our_address}");
+
+    // Send a message throught the mixnet to ourselves
+    client
+        .send_str(&our_address.to_string(), "hello there")
+        .await;
+
+    println!("Waiting for message");
+    client
+        .on_messages(|msg| println!("Received: {}", String::from_utf8_lossy(&msg.message)))
+        .await;
+}