The 15.4 update of Visual Studio has a lot of new things. Also the Fall creator update enables you to use .net Standard 2.0 in UWP apps. Adding UWP apps in the store is easy and native. But you can also pack other types and submit them as store apps.
WAP
Windows Application Packaging Project. it’s a new project template in vs15.4 You can load up the solution containing your application and add a new project of this type.
Select the target and minimum version of the Windows SDK (this is recognizable from uwp apps)
Right click applications in the solution explorer and add a reference to your main application project
Then you can use the create app packages like you would do for an UWP app
You can read more about it on the microsoft docs site
https://docs.microsoft.com/en-us/windows/uwp/porting/desktop-to-uwp-packaging-dot-net
Pro tip: visit the Microsoft Docs website more often. They are really improving lately. Like a lot!
There is just one thing I would like to point out: your developer account needs extra permissions to submit such type of application.
You will need to submit your info on this page:
https://developer.microsoft.com/en-us/windows/projects/campaigns/desktop-bridge
and they will get back to you in 6 business days.
I have submitted two apps, one for the general store and one as a business app which is only available for my colleagues in a private store. Both are still waiting for approval. Hope to hear soon from the team.
So the pro-tip of today is: make sure your dev ms account has privileges to submit a desktop bridge app to the store!
Good luck!