Configure `features` per target platform

_I am an early user of cargo-dist, and I love it!_

It would be great to be able to configure features per target as some of the platforms do not support one thing or another. For example, I don't want to build udev-dependent code for linux-musl-static builds, so I would just disable default-features and enable only the features that make sense for musl-static build.

I wish cargo support it, and then cargo-dist may not need to implement it: https://github.com/rust-lang/cargo/issues/1197

Start by reading the linked Cargo issue #1197 and reviewing cargo-dist's target-platform configuration. Determine whether Cargo now supports per-target features or whether cargo-dist must provide the behavior; done means the requested feature selection works for targets such as linux-musl-static, or the limitation is clearly documented.

Written by the indexing model from the issue text.