Update wording to avoid confusion

Author: shivansh

fern/docs/pages/customization.mdx

@@ -431,8 +431,8 @@ hints:
 * `is_sortable`: Whether the field is sortable. Requires `is_filterable` to be true.
 * `is_groupable`: Whether the field is groupable. Requires `is_filterable` to be true.
 * `order`: The order in which the field appears in the side panel.
-* `is_read_only`: Whether the field is read-only in the UI. Once created, this
-  field cannot be updated from the UI.
+* `is_read_only`: Whether the field is read-only in the UI. Once the object is created, this
+  field cannot be updated in the UI.
 * `group_name`: The group title under which field(s) appear in the side panel. In the
   example below, the fields are grouped under groups titled **Group 1** and **Group 2**.