rename interface

composer.json

@@ -8,7 +8,7 @@
     "license": "MIT",
     "autoload": {
         "psr-4": {
-            "Potter\\": "src/Potter/Contract/"
+            "Potter\\Startable\\": "src/Potter/Startable/"
         }
     },
     "authors": [

src/Potter/Startable/StartableInterface.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Potter\Startable;
+
+interface StartableInterface
+{
+    public function start(): void;
+}