Add code for demonstrating concurrency

async-concurrency/Cargo.toml

@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+trpl = "0.2.0"

async-concurrency/src/main.rs

@@ -1,3 +1,17 @@
+use std::time::Duration;
+
 fn main() {
-    println!("Hello, world!");
+    trpl::run(async {
+        trpl::spawn_task(async {
+            for i in 1..10 {
+                println!("hi number {i} from the first task!");
+                trpl::sleep(Duration::from_millis(500)).await;
+            }
+        });
+
+        for i in 1..5 {
+            println!("hi number {i} from the second task!");
+            trpl::sleep(Duration::from_millis(500)).await;
+        }
+    });
 }