Support for NPM7 workspaces (monorepo)

NPM 7 has introduced [workspaces](https://docs.npmjs.com/cli/v7/using-npm/workspaces) which allows us to manage multiple packages inside one repository without any external dependencies such as Lerna.

It would be fantastic if the auto npm implementation would support this. Basically it would need to parse the `workspaces` array in the root `package.json` and then run the commands for each workspace, e.g. `npm publish -w my-first-module`.

Could this be added?