Code review comment for lp:~hrvojem/percona-server/doc-29

   - Need different introduction because the feature is not in XB
     yet:
   - "Main goal for archiving the |XtraDB| logs is ability to later
     use them for incremental backups." - move to the end.
   - "These logs can be replayed since the last backup was taken
     with |Percona XtraBackup|." - not actually true right now.
   - And I miss a sentence(s) what does log archiving actually
     do. I.e. "InnoDB writes to the redo log files in a cyclic
     manner, so that the oldest log data is overwritten with the
     newest one. This feature makes copies of the old log files
     before they are overwritten, thus saving all the redo log for a
     write workload".
   - innodb_log_arch_expire_sec needs describing at the top as
     well. "It is possible to remove the oldest archived logs
     automatically by ... ".