Adding Customer Custom attributes creating document files

src/pages/config.md

@@ -789,6 +789,9 @@
             - [Customize form configuration](/tutorials/admin/custom-product-creation-form/configuration.md)
             - [Customize using a modifier class](/tutorials/admin/custom-product-creation-form/modifier-class.md)
         - [Create a text field attribute](/tutorials/admin/custom-text-field-attribute.md)
+        - [Create a boolean field attribute](/tutorials/admin/custom-boolean-field-attribute.md)
+        - [Create a dropdown field attribute](/tutorials/admin/custom-dropdown-field-attribute.md)
+        - [Create a multiselect field attribute](/tutorials/admin/custom-multiselect-field-attribute.md)
     - [Frontend development](/tutorials/frontend/index.md)
         - [Customize checkout](/tutorials/frontend/custom-checkout/index.md)
             - [Add a new checkout step](/tutorials/frontend/custom-checkout/add-new-step.md)
@@ -813,4 +816,4 @@
         - [Create a custom import entity](/tutorials/backend/create-custom-import-entity.md)
         - [Convert serialized to JSON](/tutorials/backend/convert-serialized-data.md)
         - [Copy fieldsets](/tutorials/backend/copy-fieldsets.md)
-        - [Modify media library folder permissions](/tutorials/backend/modify-image-library-permissions.md)
+        - [Modify media library folder permissions](/tutorials/backend/modify-image-library-permissions.md)