Feedback requested: async APIs

[cljoly]

This crate supports tokio-rusqlite when the alpha-async-tokio-rusqlite feature is enabled. This feature is marked alpha because there is no commitment to API stability, contrary to the rest of the package. To stabilize it, we need your help!

Please share any feedback you may have (what is easy to use, what could be better, what causes pain…) in this discussion.