initial COmmit: Add KB Antora Importer plugin files

kb-antora-importer/includes/Access/AccessController.php

@@ -0,0 +1,25 @@
+<?php
+declare(strict_types=1);
+
+namespace KbAntoraImporter\Access;
+
+use KbAntoraImporter\Plugin;
+
+final class AccessController
+{
+    public function canView(): bool
+    {
+        $settings = Plugin::settings();
+
+        return '1' === $settings['public_docs'] || is_user_logged_in() || current_user_can('view_kb_docs');
+    }
+
+    public function enforce(): void
+    {
+        if ($this->canView()) {
+            return;
+        }
+
+        auth_redirect();
+    }
+}