Update interface with docblocks and a new namespace

src/Entity/Interface/SearchableInterface.php

@@ -1,11 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Pcm\SearchBundle\Entity\Interface;
-
-interface SearchableInterface
-{
-    public function getSearchTitle(): string;
-    public function getSearchValues(): array;
-}

src/Interface/SearchableInterface.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pcm\SearchBundle\Interface;
+
+interface SearchableInterface
+{
+    /**
+     * This entity's human-readable title to be shown in search results.
+     */
+    public function getSearchTitle(): string;
+
+    /**
+     * The string values to index for this entity
+     *
+     * Each value is concatenated into the fulltext index, so include any field a user might search by.
+     *
+     * @return string[]
+     */
+    public function getSearchValues(): array;
+}