Add PHP version of kata

php/src/Performance.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Theatrical;
+
+class Performance 
+{
+    public string $play_id;
+    public int $audience;
+
+    public function __construct($play_id, $audience)
+    {
+        $this->play_id = $play_id;
+        $this->audience = $audience;
+    }
+}