Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 default_scenario(Arg1)

 issue(Arg1, Arg2)

 scope(Arg1, Arg2)

 target(Arg1, Arg2)

 yes_no(Arg1, Arg2)

 numeric_field(Arg1, Arg2, Arg3, Arg4)

 scenario_numeric_keys(Arg1)