add changelog entry for work on #30

Author: ghazi-git

docs/changelog.md

@@ -14,6 +14,8 @@ You can find [more information about that in the documentation](openapi.md#custo
 - Don't generate error responses for OpenAPI callbacks.
 - Make `_should_add_http403_error_response` check if permission is `IsAuthenticated` and 
 `AllowAny` via `type` instead of `isinstance`
+- Don't collect error codes from nested `read_only` fields
+
 ## [0.12.4] - 2022-12-11
 ### Fixed
 - account for specifying the request serializer as a basic type (like `OpenApiTypes.STR`) or as a