I am wondering how to go about having users create user accounts and then use those accounts to create payrolls. A payroll is a set of payslips associated with a certain user. What I currently have is an auth system that uses openID. I am thinking of associating a payroll and subsequently the payslips in the payroll with the email address of the currently logged in user but I am not sure how to go about that. Second, I don't want to limit users to the kind of allowances and deductions they can enter. So in the web form they are going to have a button they can use to add fields of a key value pair for example one can add an allowance field and add [House_allowance] [3000]. This will be part of a payslip. However, these extra fields can't be added to the Payslip type because the additional fields are added through JS. So I shall have a separate type `Extra` to store this map where `data Extra = Extra { Allowance:: [(Text, Int)], Deduction :: [Text, Int]}` I can convert this map to a PersistentValue in GHCI but I have no idea how to represent it in the config/models file. How can I show in my config/models that I want to store this map in the DB and associate it with the relevant payslip?