Building for multiple platforms

[Neils]

> Since your project is already on GitHub, I think the easiest 
> solution would be to use GitHub Actions [1] + setup-dlang 
> action [2] + upload-release-asset action [3]  to automate the 
> whole process.
>
> [1]: https://help.github.com/en/actions
> [2]: https://github.com/mihails-strasuns/setup-dlang
> [3]: https://github.com/actions/upload-release-asset

This looks very promising, thanks!