Update author name and remove author email field in package.json

[RRosio]

To resolve #36 we can update the author name to JupyterFsspec Contributors. As for author email, the field is required in the copier template, while not so in the package.json. As hatch validates the email address field, so adding instead a link to where issues should be reported will not be accepted. We can instead remove the email field from the package.json while keeping a tellingly non-working email in the copier configuration file.