EPN: ship the configuration file.
    
    Ship and install /etc/ipa/epn.conf.
    Minor fixes to the associated man page.
    
    Fixes: https://pagure.io/freeipa/issue/8374
    Signed-off-by: François Cami <fcami@redhat.com>
    Reviewed-By: Alexander Bokovoy <abbra@users.noreply.github.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>