- Recommend max_allowed_packet=1G which is the same as the default client
  value.
- Remove thread_concurrency removed in 10.5.
- Remove query cache, not recommended practice anymore.
- Remove binlog_*, should not recommend those too easily but rather require
  the database administrator to read up on those themselves.
- Remove chroot setting, not relevant in modern container era.
- Show explicitly innodb_buffer_pool_size example as the most likely thing
  a database administrator should change.
- Don't recommend rate limiting in slow log, logging once in a 1000
  would not be optimal for the basic case, hence bad example.
- Install the example configs in /usr/share/mysql.
- Use correct path /run/ instead of /var/run/.