Add support for parent categories in documentation management

- Update `DocumentationCategoryService::create` to accept an optional `parentId` parameter.
- Introduce `CreateRequest` for validating parent category input.
- Adjust controller actions to handle parent category information.
- Restructure templates under `documentation-versions` for better organization.

app/application/resources/views/admin/projects/documentation-versions/documentation-categories/create.blade.php

@@ -3,14 +3,14 @@
     {{ __('admin-sections.Project') . ': ' . $project->name . ' (' . $version->title . ')' }}
 @endsection
 <x-admin.layout>
-    @include('admin.projects.documentation-categories._top')
+    @include('admin.projects.documentation-versions.documentation-categories._top')
     <div class="row">
         <div class="col-12 mb-4">
             <div class="card border-0 shadow components-section">
                 <div class="card-body">
                     <h3 id="category" class="mb-4">{{ __('admin-sections.Categories') }}</h3>
                     <form method="post" action="{{ route('admin.projects.documentation-versions.categories.store', ['project' => $project->id, 'version' => $version->id]) }}">
-                        @include('admin.projects.documentation-categories._from')
+                        @include('admin.projects.documentation-versions.documentation-categories._from')
                     </form>
                 </div>
             </div>