Support for Crystal Shards

[Sija]

Shards are packages for the Crystal programming language, intended to be consumed by the package manager of the same name. Shards are to Crystal, what Gems are to Ruby :)

[stefanbuck]

According to the internet, it's a niche programming language for high-performance applications targeting mostly Ruby developers. Sadly, OctoLinker itself isn't used by that many Ruby developers. I think there is not much demand for it (at least right now).

I'll keep this issue open to track discussion around cancellation, but I don't expect we'll work on it in the immediate future.