Missing documentation about configuring user/group mapping on AO

Configuring LDAP is lacking documentation in regards to user and group mapping like: Base, Filter, Scope

The only Autonomous Operator documentation covers the generic LDAP configuration, as mentioned in https://docs.couchbase.com/operator/current/reference-couchbasecluster.html#spec-security-ldap and using the template `userDNMapping` for mapping users to a group, as mentioned on https://docs.couchbase.com/server/current/manage/manage-security/configure-ldap.html#template.