add solutions for chapter 10

implementation/10/src/Action/Hello.php

@@ -0,0 +1,24 @@
+<?php declare(strict_types=1);
+
+namespace Lubian\NoFramework\Action;
+
+use Lubian\NoFramework\Service\Time\Clock;
+use Psr\Http\Message\ResponseInterface;
+
+final class Hello
+{
+    public function __invoke(
+        ResponseInterface $response,
+        Clock $clock,
+        string $name = 'Stranger'
+    ): ResponseInterface
+    {
+        $body = $response->getBody();
+
+        $body->write('Hello ' . $name . '!<br />');
+        $body->write('The time is: ' . $clock->now()->format('H:i:s'));
+
+        return $response->withBody($body)
+            ->withStatus(200);
+    }
+}