Add a nice workflow

[raldone01]

This workflow does the following:

• On push on main a prerelease is created and continuously updated with the latest files.
• If a tag v1.1.1 is pushed a normal release is created.
• Pull requests are checked for a passing build.

Please consider adding this because linux users wanting to test dxvk may not have a windows machine readily available.

[WinterSnowfall]

linux users wanting to test dxvk may not have a windows machine readily available.

...a "readily available windows machine" is not required for building the tests, the usual MinGW setup (also used for building dxvk) works just as well on Linux. Also keep in mind these tests are only there for development purposes, they're not intended for regular users, which is why they sit in a separate repository.