Mention images are bootc compliant in docs/readme

[SohamG]

I noticed that ucore images derive from fedora-coreos. I think having bootc images deriving from fedora-bootc would also be a good addition. Is this a planned feature?
I rebased from a bootc system to ucore and it seems that the ucore:stable image is a bootc image given the containers.bootc label.

I wonder if this is a documentation error?

[bsherman]

I welcome a PR to add something to the docs.

Since ucore only builds upon Fedora CoreOS, we should be bootc compliant if it is.

[SohamG]

Thanks for the reply. I think given how new everything is combined with the fact that fedora coreos doesnt advertise its bootc compliance well led me to this confusion. I'll see what I can do in terms of a PR. (Can close the issue if desired)