Add an initial test for counting past talks

src/TwigExtension/TalkExtension.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\TwigExtension;
+
+use Illuminate\Support\Collection;
+
+final class TalkExtension
+{
+    public function getPastTalksCount(array $talks = []): int
+    {
+        $talkCollection = new Collection($talks);
+
+        return $talkCollection->count();
+    }
+}