Add domain authentication method to Knowledge bases

Within ideas portals you have the option to enter a series of email domains to manage who can authenticate into the portal.

This would be a helpful authentication method to allow you to quickly provide access to KBs for only select customers, without needing to set up SSO or know all the emails of users who may need to access the KB.

This would work in the same way as the "Employees" authentication method offered in ideas portals.