Add Taxon documentation to OpenAPI specification (#19059)

| Q               | A
|-----------------|-----
| Branch?         | 2.2
| Bug fix?        | no
| New feature?    | no
| BC breaks?      | no
| Deprecations?   | no
| Related tickets | fixes #19020
| License         | MIT

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src/Sylius/Bundle/ApiBundle/OpenApi/Documentation/TaxonDocumentationModifier.php

@@ -0,0 +1,49 @@
+<?php
+
+/*
+ * This file is part of the Sylius package.
+ *
+ * (c) Sylius Sp. z o.o.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Sylius\Bundle\ApiBundle\OpenApi\Documentation;
+
+use ApiPlatform\OpenApi\OpenApi;
+
+final class TaxonDocumentationModifier implements DocumentationModifierInterface
+{
+    public function __construct(private string $apiRoute)
+    {
+    }
+
+    public function modify(OpenApi $docs): OpenApi
+    {
+        $path = sprintf('%s/shop/taxons', $this->apiRoute);
+
+        $paths = $docs->getPaths();
+        $pathItem = $paths->getPath($path);
+        $operation = $pathItem?->getGet();
+        if (null === $operation) {
+            return $docs;
+        }
+
+        $operation = $operation
+            ->withSummary('Retrieves the collection of enabled Taxon resources for the current channel.')
+            ->withDescription(
+                'Returns the direct enabled children of the Menu Taxon configured for the current channel. ' .
+                "The Menu Taxon is resolved from the active channel configuration. " .
+                "If no Menu Taxon is configured for the channel, the default code is used.",
+            )
+        ;
+
+        $pathItem = $pathItem->withGet($operation);
+        $paths->addPath($path, $pathItem);
+
+        return $docs->withPaths($paths);
+    }
+}

src/Sylius/Bundle/ApiBundle/Resources/config/integrations/swagger.xml

@@ -106,5 +106,10 @@
         <service id="sylius_api.open_api.documentation_modifier.address_log_entry" class="Sylius\Bundle\ApiBundle\OpenApi\Documentation\AddressLogEntryDocumentationModifier">
             <tag name="sylius.open_api.modifier" />
         </service>
+
+        <service id="sylius_api.open_api.documentation_modifier.taxon" class="Sylius\Bundle\ApiBundle\OpenApi\Documentation\TaxonDocumentationModifier">
+            <argument>%sylius.security.api_route%</argument>
+            <tag name="sylius.open_api.modifier" />
+        </service>
     </services>
 </container>