Rust-gpu in crates.io is misleading

[cybersoulK]

as a beginner, i will try to use rust-gpu 0.1 in crates.io, and think it's outdated in crates.io.
We can update the rust-gpu, or provide links and explanation to the different crates (spirv-builder and spirv-std)

[Eduard-Mihai Burtescu]

and think it's outdated in crates.io

To be clear, there's nothing there, it's just reserved. It might be good to yank it (as long as that keeps the reservation), which would prevent people from accidentally trying to use it (cc @repi).

We may still end up using it, e.g. if this RFC lands, it could become a namespace crate:

• rust-lang/rfcs#3243

[Johan Andersson]

have published an update of it that links to this repo instead, and yanked the versions (good idea!).