By setting --waldir in "pg_basebackup_options", standbys cloned using
pg_basebackup would have their WAL directory set to the specified
location and symlinked from the data directory.
This commit causes repmgr to honour that setting even when cloning
from Barman.
A more generic option name to cover pre- and post-Pg12 replication
configuration methods.
--recovery-conf-only is retained as an alias for backwards
compatibility.
- remove references to repmgr 4.0.4 (present because feature
was added in a minor release, but that's a long time ago)
- note configuration is appended to postgresql.auto.conf