release tags that we can depend on from other projects' Package.swift

[marcrasi]

I'm running into a specific problem that would be fixed by release tags: https://github.com/tensorflow/swift-models/pull/640 causes error "swift-benchmark is required using two different revision-based requirements, which is not supported" if we try to depend on swift-models (which depends on a specific commit hash of swift-benchmark) and penguin (which depends on master of swift-benchmark at the same time (as we do in SwiftFusion).

[shabalind]

Hi @marcrasi, thanks for raising this issue, we need to do a 0.1 release soon!

[MaxDesiatov]

Hi @shabalind, any updates on this?