Small corrections to stored_fields docs. (elastic#53247)

* Fix a reference to the 'field' option.
* Remove claim about detecting script fields.
* Specify that object fields will just be ignored.

docs/reference/search/request/stored-fields.asciidoc

@@ -40,12 +40,7 @@ If the requested fields are not stored (`store` mapping set to `false`), they wi
 
 Stored field values fetched from the document itself are always returned as an array. On the contrary, metadata fields like `_routing` are never returned as an array.
 
-Also only leaf fields can be returned via the `field` option. So object fields can't be returned and such requests
-will fail.
-
-Script fields can also be automatically detected and used as fields, so
-things like `_source.obj1.field1` can be used, though not recommended, as
-`obj1.field1` will work as well.
+Also only leaf fields can be returned via the `stored_fields` option. If an object field is specified, it will be ignored.
 
 NOTE: On its own, `stored_fields` cannot be used to load fields in nested
 objects -- if a field contains a nested object in its path, then no data will