Update documentation for remove_uploads function to clarify usage and parameters

Author: Flo0807

lib/backpex/fields/upload.ex

@@ -119,13 +119,15 @@ defmodule Backpex.Fields.Upload do
     ],
     remove_uploads: [
       doc: """
-      A function that is being called after saving an item to be able to delete removed files.
+      A function that is being called after editing an item to be able to delete removed files.
+
+      Note that this function is not invoked when an item is deleted. Therefore, you must implement file deletion logic in the `c:Backpex.LiveResource.on_item_deleted/2` callback.
 
       **Parameters**
 
       * `:socket` - The socket.
       * `:item` (struct) - The item without its changes.
-      * `removed_entries` (list) - A list of removed uploads during edit.
+      * `removed_entries` (list) - A list of removed uploads during edit. The list only contains files that existed before the edit.
 
       **Example**