tests: add test for help output

tests/Unit/Console/Help.php

@@ -0,0 +1,12 @@
+<?php
+
+use Pest\Console\Help;
+use Symfony\Component\Console\Output\BufferedOutput;
+
+it('outputs the help information when --help is used', function () {
+    $output = new BufferedOutput();
+    $plugin = new Help($output);
+
+    $plugin();
+    expect($output->fetch())->toContain('Pest Options:');
+});