CI with Github Actions to build nightlies archives

[yarik2720]

Adding this workflow allows to download already compiled plugins with needed files in archive.
Suddenly this requires to change project path hierarchy

[Alienmario]

I appreciate the effort, but the project structure is intentional to aid development.
It should be the build script's job to organize the output archive.

[yarik2720]

@Alienmario now switched to another builder, that accepts current file hierarchy

[Alienmario]

Looking good, permission to experiment? (I'm a ci noob)

[yarik2720]

@Alienmario it start automatically work once this is in your repository, even not in master branch. CI will make build (based by yml settings) on every commit push and pull requests in those branches, where CI files already persist.
You can see results of every commit on branch ci here: https://github.com/yarik2720/SourceCoop/actions

[Alienmario]

Yeah I'm aware, was more talking about the yml editing.
Anyway I'll merge it in now and see if I can expand on it after.
This will surely make many people happy, thank you.