How does the client work - ParkitectNexus/ParkitectNexusClient GitHub Wiki
When you've added your mod to ParkitectNexus, people can download your mod with the "Install with ParkitectNexus Client" button. This button will call the client with information on which repository it needs to download.
The client will make a request to GitHub and checks all releases on the repository, it will download the latest created release. So you can choose your own version numbering style.
Also see Preparing for release