add pdf reader modul

src/Knowledge/Extractor/DocumentExtractorInterface.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Knowledge\Extractor;
+
+interface DocumentExtractorInterface
+{
+    public function supports(string $extension): bool;
+
+    public function extract(string $path): string;
+}