Designate Consistent Group of Maintainers for this Repository

[danielhelfand]

It seems as though there is not a consistent group working to maintain this repository. I think there are a lot of opportunities to make improvements to azure-sdk-for-go-samples, but I think that making contributions to the repository is rather difficult. It's unclear who to reach out to for a pull request review, and it does seem as though pull requests are very frequently ignored.

My ask would be to, at bare minimum, have a designated team in place that will review pull requests and issues of this repository at least once a week. It might also help to specify in the main README.md or CONTRIBUTING.md a good way to get in contact with the maintainer team.