add thread test

thread-test/src/main.rs

@@ -0,0 +1,10 @@
+use std::thread;
+
+// https://zhuanlan.zhihu.com/p/89716165
+fn main() {
+    let child = thread::spawn(move || {
+        println!("Hello World!");
+    });
+    let _res = child.join().unwrap();
+    println!("Finished!");
+}