this is a backward incompatible change, all previous file based IP/network
lists will not work anymore
Signed-off-by: Nicola Murino <nicola.murino@gmail.com>
add groups section in the getting started guide.
Suggest to prefer configuration with env vars instead of modifying
the default configuration file
Signed-off-by: Nicola Murino <nicola.murino@gmail.com>