[Docker Registry] Move container from lpetrut/rust_win_buildtools to rust-vmm

[bonzini]

Currently the container is hosted on Docker Hub in Lucien's profile. We now have a rust-vmm profile on Docker Hub and the container should be moved there.

In doing so we will also need to:

• modify all existing Buildkite pipelines that are pulling the container
• modify the readme of this repository
• modify the readme of all repositories that are mentioning it (kvm-ioctls, vm-virtio, others?)

[bonzini]

See #7 for the actual Dockerfile.

[petrutlucian94]

The docker file has been copied here: #40.

[andreeaflorescu]

For this to be closed we still need to publish the container under the rust-vmm docker hub org.