🛠️ Repo: Lint/validate JSDoc

[boneskull]

I'm getting bit with failing documentation builds because I'm writing docstrings that JSDoc doesn't like (specifically, TS-style). But there's no linting happening before getting to Netlify.

We may be able to make JSDoc just check the syntax and exit (and make it part of the lint scripts).

This is moot if we want to move forward with maintaining our own TS types (for which there is an open PR that I cannot find atm). That will most likely require dumping JSDoc in lieu of a TS-based API doc generator, because the types aren't really compatible.

There may be another ESLint-based solution, but I'm not sure. If someone else thinks this is worth doing, please add help wanted label, but I don't want anyone to pick this up unless there's agreement that it's worth bothering with (if we're going to eventually have to drop JSDoc).

[JoshuaKGoldberg]

Marking as accepting PRs in lieu of #4154. Even if the whole repo were to be converted to TypeScript it'd still be good to have some linting for JSDocs (i.e. eslint-plugin-jsdoc).