AFAIK you cannot publish a Windows service in the store. Store apps don't have that functionality. Furthermore store apps are generally installed per user and a normal user cannot install services. Your store app can rely on Windows services. But as mentioned in the Store Policies you are not allowed to rely on non-MS services. If you have that need you must document it as part of your certification process and MS will decide whether it is allowed or not.
If you really want to publish your app via the Windows Store then the closest you can get is creating a background task that runs. Refer to the docs here. But note that this is not a service and won't behave as such.
If you need to install a service then you'll want to use a standard Windows Installer from one of the popular installer companies. Of course at that point then it probably is no longer necessary to use the Windows Store at all.