Fixes missed example and config for extractors.

examples/extractors/src/path_three.rs

@@ -0,0 +1,23 @@
+use actix_web::{web, App, HttpRequest, HttpServer, Result};
+
+// <path-three>
+fn index(req: HttpRequest) -> Result<String> {
+    let name: String = req.match_info().get("friend").unwrap().parse().unwrap();
+    let userid: i32 = req.match_info().query("userid").parse().unwrap();
+
+    Ok(format!("Welcome {}, userid {}!", name, userid))
+}
+
+pub fn main() {
+    HttpServer::new(|| {
+        App::new().route(
+            "/users/{userid}/{friend}", // <- define path parameters
+            web::get().to(index),
+        )
+    })
+    .bind("127.0.0.1:8088")
+    .unwrap()
+    .run()
+    .unwrap();
+}
+// </path-three>