deprecation in favor of https://github.com/containers/toolbox

[cgwalters]

We'd like to converge efforts to https://github.com/containers/toolbox

Please comment on e.g. containers/toolbox#302 if you're a maintainer of this project and would like to continue to contribute.

Further, also a good opportunity to ensure you're following the repo, etc.

[yuqi-zhang]

I'm definitely +1 on this. Do we plan on supporting existing RHCOS behaviour? Or will we be modifying that to the unified toolbox workflow?

[miabbott]

@yuqi-zhang Yeah, we want to retain the existing RHCOS behavior (or something like it). See the most recent PR that @dustymabe merged into the containers/toolbox repo - containers/toolbox#308

[debarshiray]

Toolbox now has a reasonable migration path for coreos/toolbox users. See: containers/toolbox#689