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.
- OEMID is a module for configuring phase-0 things for an OEM,
like batch-ID. This is just a stub.
- Currently planned functionality is limited to just batch-ID.
