Pre-fill email address in kratos welcome email

In the welcome email from kratos, there's a link to the recovery flow that's automatically been created. This is valid for one hour. To help out people who process the email later, we include a link to start a new recovery flow. Now that we support pre-filling the email address via an ?email= url parameter, we should do that in that email template, making the life of the user a little bit easier.