fix modules and FileUpload class

kernel/modules/post/models/forms/CreatePostForm.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace kernel\modules\post\models\forms;
+
+use kernel\FormModel;
+
+class CreatePostForm extends FormModel
+{
+    public function rules(): array
+    {
+        return [
+            'content' => 'required|min-str-len:1',
+            'user_id' => 'required',
+        ];
+    }
+}