Publish supporting files with package

Recently I had used the progress bar script that was shared in the forum and it contains a dll file that needs to be loaded.

I want to publish my package with the progress bar node hence i will need the supporting dll file to be published
How do we make sure that the user who downloads my node will have the dll file and where can i see these support files.

see this:

I think there is a section on adding more than one file or dll to the package.