Task 1: Calculator init

tasks/task_01/src/Operation.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App;
+
+enum Operation: string {
+    case ADD = 'add';
+    case SUBTRACT = 'subtract';
+    case MULTIPLY = 'multiply';
+    case DIVIDE = 'divide';
+}