fix: unable to install games on linux

[scrlkx]

There is a issue when installing games on Linux. I described it in #299.

Fixes #299

[zamitto]

Finally got able to install a linux disto on my PC, will test your PR today

[zamitto]

Gonna post here the same commend I posted on #299 just to make it more visible:

May I suggest something?

1. If there is a setup.exe inside the gamePath, we call wine ${setupPath} and return
2. If there is not a setup.exe but there is any other .exe file, we call wine ${gamePath}
3. If not, we open the directory using shell.openPath(gamePath)

The Windows conditional remains the same as it is in your PR. These checks should happen after that.