fix error message

Author: mununki

compiler/syntax/src/jsx_v4.ml

@@ -1294,7 +1294,12 @@ let transform_structure_item ~config item =
     | _, [_] ->
       Jsx_common.raise_error ~loc:pstr_loc
         "Components cannot be defined as externals when using \
-         @react.componentWithProps. Please use @react.component instead."
+         @react.componentWithProps.\n\n\
+         If you intended to define an external for a React component using a \
+         props type,\n\
+         use the type React.component<props> instead.\n\
+         Alternatively, use @react.component for an external definition with \
+         labeled arguments."
     | [_], [] ->
       check_multiple_components ~config ~loc:pstr_loc;
       check_string_int_attribute_iter.structure_item