Proposal: Create a new oras-credentials-go repository

[shizhMSFT]

As discussed in the community meeting on oras-project/oras-go#413, we are going to create a repository oras-project/oras-credentials-go for developing a golang SDK to access docker-formatted credentials for oras-go v2.

I also proposing that the new SDK repo can be maintained by the same crew of oras-go.

[FeynmanZhou]

This proposal has been discussed and approved in the community meeting on Jan 31. According to the ORAS governance doc, @shizhMSFT as an org owner can create this new repository as a subproject.

The remaining items for this proposal are to define the governance process and subproject owners/maintainers for this new repo. I will raise a PR to add the related documents to the ORAS governance doc.

[SteveLasker]

LGTM

[shizhMSFT]

Created a new repository: https://github.com/oras-project/oras-credentials-go