Documentation update request on rpl_semi_sync_master_wait_point

Documentation on possible rpl_semi_sync_master_wait_point values could be more detailed, it is missing some of the information that can be found in the MySQL manual:

See:

https://dev.mysql.com/doc/refman/5.7/en/replication-options-master.html#sysvar_rpl_semi_sync_master_wait_point

vs:

https://mariadb.com/kb/en/library/semisynchronous-replication/#rpl_semi_sync_master_wait_point