Update readme file

[dgarijo]

The guidelines indicate that the maintainers in a readme file should be optional. I think this file should be required, not optional. We also should require the github id of the maintainers.

The reason for this request is because we have been receiving several updates from w3ids, and not having a readme file makes me having to go to the commit history of that folder, which takes more time. The reason for using the github id in addition to email is because sometimes the author of the pull request has an id that differs significantly from their name and email.