Need a way to document module namespace objects

Problem

API-Extractor and TSDoc support adding a documentation comment to the entry point module, but not to individual re-exported modules. Modern bundlers and other tooling vastly prefer module namespace objects over static classes because they can be fully statically analyzed and tree-shaken. However, the current model does not provide a way to apply a documentation comment to an individual module that gets applied to the module namespace object (the result of import * as ... or export * as ... expressions).

functions/foo.ts

export function foo();

functions/index.ts

export { foo } from './foo';

Functions.ts

import * as Functions from './functions/index';
// How do I put a comment on this export?
export { Functions };

Start by comparing the namespace-object examples in functions/foo.ts, functions/index.ts, and Functions.ts, then review how API-Extractor and TSDoc currently attach comments to entry point modules. Done means the model provides a documented way to attach a comment to the re-exported Functions module namespace object.