Document how to customise a profile

[d6y]

Perhaps.

E.g., https://github.com/d6y/instant-etc/blob/master/src/main/scala/main.scala#L9-L45

[d6y]

See also: http://slick.lightbend.com/doc/3.3.0/datetimetypes.html for notes regarding dates/times

[d6y]

See also an example of adding IS: https://stackoverflow.com/a/64164900/154248