Doc rst file for parsers/sys_block.py is missing

[JoySnow]

insights/parsers/sys_block.py 's doc rst file is unexist under docs/shared_parsers_catalog .

Need to add it.

The following files under insights/parsers are also have no related doc rst files in docs/shared_parsers_catalog :

 'amq_broker.py',
 'branch_info.py',
 'gcp_network_interfaces.py',
 'metadata.py',
 'neutron_ml2_conf.py',
 'nova_conf.py',
 'oracle.py',
 'ovirt_engine_confd.py',
 'ovs_vsctl_show.py',
 'password.py',
 'pci_rport_target_disk_paths.py',
 'pluginconf_d.py',
 'rhn_charsets.py',
 'rhn_entitlement_cert_xml.py',
 'rhn_hibernate_conf.py',
 'rhn_schema_stats.py',
 'rhsm_log.py',
 'route.py',
 'rpm_vercmp.py',
 'scsi.py',
 'sestatus.py',
 'systemd',
 'systemid.py',
 'tags.py',
 'yum_repos_d.py',

Need to add these accordingly.