My favourite page is "Specifying source files" [0], which seems like an important thing for an installer, but all this page contains is:

> To be written. To volunteer, leave a comment at the related issue on GitHub.

If you start with Visual Studio, create a project with their (free) plugin, and configure Heat [1], you might get a working installer.

[0]: https://wixtoolset.org/docs/tools/payloads/

[1]: https://wixtoolset.org/docs/tools/heat/