Small cleanup for easier local development.

Added a dev/ folder which will hold all the needed files for local
development.

dev/server.php

@@ -0,0 +1,11 @@
+<?php declare(strict_types=1);
+
+$uri = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
+
+$file = dirname(__DIR__) . '/public' . $uri;
+
+if (is_file($file)) {
+    return false;
+}
+
+require dirname(__DIR__) . '/index.php';