Fixed Syntax for folder permission's JSON

docs/sources/http_api/folder_permissions.md

@@ -105,7 +105,7 @@ POST /api/folders/nErXDvCkzz/permissions
 Accept: application/json
 Content-Type: application/json
 Authorization: Bearer eyJrIjoiT0tTcG1pUlY2RnVKZTFVaDFsNFZXdE9ZWmNrMkZYbk
-
+{
   "items": [
     {
       "role": "Viewer",