Broken link in docs (index.md)

[larsks]

docs/index.md contains the following:

### Base images

Many users will be more interested in base (container) images.

For pre-built base images:

* [Fedora CoreOS](https://quay.io/repository/fedora/fedora-coreos) can be used as a base image; you will need to [enable bootc](https://github.com/coreos/rpm-ostree/blob/main/docs/bootc.md) there.
* There is also an in-development [centos-boot](https://github.com/centos/centos-boot) project.

The URL https://github.com/coreos/rpm-ostree/blob/main/docs/bootc.md leads to a 404 error.

[vrothberg]

Thanks for reaching out, @larsks.

The doc has been removed by coreos/rpm-ostree@3abb647 and I am not 100 percent sure what to do. @cgwalters is the important part the $ ln -sr /usr/bin/rpm-ostree /usr/bin/bootc of the previous doc?