Data Package is a standard consisting of a set of simple yet extensible specifications to describe datasets, data files and tabular data. It is a data definition language (DDL) and data API that facilitates findability, accessibility, interoperability, and reusability (FAIR) of data.
In both version of Frictionless Data documentation (v1 and v2) the JSON Data Resource is mentioned with recipes.
https://datapackage.org/recipes/json-data-resources/
To me it seems better to put this as standalone specification (despite of being rather simple).