Yep, because edition 2018 hasn't been stabilized yet. Rust 1.31 stable will be released on 2018-12-06.
I'd love to, but I, m already working on a 60+h per week basis as it is.
Every now and again when I need something nonexistent I can make the case to my boss that it is worthwhile to contribute FOSS code, but something like the RLS takes huge amounts of effort and every step is just a little one (a direct consequence of its complexity).
Besides, I was merely informing about the feasibility 