Create an installer

It would be nice to use Github Actions to automatically generate installers on each release. 

As far as I know, there are two solutions available.

* Inno setup https://jrsoftware.org/isinfo.php
* Nullsoft https://nsis.sourceforge.io/Main_Page https://nsis.sourceforge.io/Simple_tutorials ([used by Anki](https://github.com/ankitects/anki/blob/main/qt/bundle/win/anki.template.nsi)) 