Key groups are named sets of related keys. Each key can belong
to at most one group that is specified a key creation
time. Key groups offer a convenience for user interaction.
val v :
?loc:B0.Def.loc -> ?doc:string -> string -> t
v n ~docis a key group with unique name
Warning. Groups must be defined at toplevel and are subject
to namespacing, see details.
val none :
noneis the group attached to keys that do not specify an explicit group. Its name is
val keys :
t -> B0.Conf.Key.t list
keys gare the keys that belong to group