Fix the following errors in section "*PostgreSQL parameters controlled by Patroni*":
1. Supplement the missing parameter `wal_log_hints`.
2. In fact, these controlled parameters are written into `postgresql.conf`.
3. In fact, these controlled parameters are passed as a list of arguments to the `postgres` (not `pg_ctl start`).
4. Add a note about that `wal_keep_segments` and `wal_keep_size` are not passed to the `postgres`.
