add attribute service_name to documentation of object service
add attribute service_name to documentation of object service

lazyfrosch/puppet-icinga2,Icinga/puppet-icinga2-rewrite,lazyfrosch/puppet-icinga2,Icinga/puppet-icinga2,lazyfrosch/puppet-icinga2,Icinga/puppet-icinga2-rewrite,Icinga/puppet-icinga2-rewrite,Icinga/puppet-icinga2