If you look at the solution, it directly answers your question. The new topic you opened isn't necessary and it is correct that people should be directed here.
You can try github-files-fetcher, it is a command line tool which downloads a single folder or file from a GitHub repo.
Think a real scenario: you were visiting the following webpage page and wanna download the `async` subdirectory alone.
With The `github-files-fetcher`, you should first copy the `url` of that page, which is https://github.com/reduxjs/redux/tree/master/examples/async, and then run the command below in command line: