Add artifactBundle to release process

[utahwithak]

It would be nice to have a artifactBundle zip be vended as part of the release. For me this would be specifically for usage in swift package manager. It could then be pulled down directly as a binary target and used directly from plugins without pulling in packages or dependencies.

It would be nice to have this option available for dependency collisions as well.

Technically I'm not entirely sure what this means. I am able to do this with SwiftLint by doing this:

        .binaryTarget(
            name: "SwiftLintBinary",
            url: "https://github.com/realm/SwiftLint/releases/download/0.50.3/SwiftLintBinary-macos.artifactbundle.zip",
            checksum: "abe7c0bb505d26c232b565c3b1b4a01a8d1a38d86846e788c4d02f0b1042a904"
        ),

Attempting to do the same with the 2.0.1 release results in an error about unknown extension of docset, which seems like it is just not picking up the right thing. Inspecting the SwiftLint zip it appears to have a single folder of the release name followed with the bin folder and binary

[InkyTsar]

Sourcery-2.0.1.artifactbundle.zip
Until it is fixed, I'm attaching self-made artifactbundle for my own needs :)

[markst]

+1

[markst]

@anytypeio not sure if this helps you too

[erichoracek]

I uploaded an artifactbundle for the latest release here by downloading Sourcery-2.0.2.zip, extracting the binary, and then running the rake release:artifactbundle from #1155! Hope that helps folks that need an artifact bundle for the latest release

EDIT: Had to make one small fix to the artifactbundle generation logic in #1182, the artifactbundle included on 2.0.2 should be up to date now