[Issue 9614] Admin guide does not document olcMultiVal

https://bugs.openldap.org/show_bug.cgi?id=9614

--- Comment #2 from Quanah Gibson-Mount quanah@openldap.org --- • 9da2307d by Quanah Gibson-Mount at 2021-07-26T16:36:34+00:00 ITS#9613, ITS#9614 - Document multival, idlexp, and maxentrysize options to slapd-mdb

multival, idlexp, and maxentrysize are all new options as of OpenLDAP 2.5 that were missing from the admin guide. Add these options and additional information beyond what is found in the man pages as appropriate.

Also fixed some discrepencies between the slapd.conf and slapd-config admin guide sections on the Database backends as well as missing information in that section.