Add example for using actix

src/main.rs

@@ -1,4 +1,18 @@
+use actix_web::{web, App, HttpRequest, HttpServer, Responder};
+
+fn greet(req: HttpRequest) -> impl Responder {
+    let name = req.match_info().get("name").unwrap_or("World");
+    format!("Hello {}!", &name)
+}
 
 fn main() {
-    println!("Hello, world!");
+    HttpServer::new(|| {
+        App::new()
+            .route("/", web::get().to(greet))
+            .route("/{name}", web::get().to(greet))
+    })
+        .bind("127.0.0.1:8000")
+        .expect("Can not bind to port 8000")
+        .run()
+        .unwrap();
 }