In spite of there being considerable documentation sometimes in the
config file, we go with CC0 because we don't want the notion of
'derived work' of a config file.
The example `settings.conf` is also CC0. Add some docs to
it while we're at it.
- Allow just a name entry, instead of requiring an object
entry; this makes "foo" equal to { name: "foo", runlevel: "default" }
and simplifies more for the straightfoward case of #974.
- Based on comments from #974, follow the configuration
scheme from services-systemd, so with separate lists
"services" and "disable". This ties it **slightly**
less closely to the commands passed to rc-config.
- If runlevel isn't set (at all) then use "default". For
most systems that do not use multiple runlevels, this
simplifies the configuration to just a list of service names
to add or delete.
