[InterNetNews/inn] 190e8c: Mention inndf in overview documentation

[Julien ÉLIE]

  Branch: refs/heads/2.7
  Home:   https://github.com/InterNetNews/inn
  Commit: 190e8c320eda75ef45db33350a41ce1f9ad8536a
      https://github.com/InterNetNews/inn/commit/190e8c320eda75ef45db33350a41ce1f9ad8536a
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2023-03-18 (Sat, 18 Mar 2023)

  Changed paths:
    M doc/pod/ovdb_stat.pod
    M doc/pod/ovsqlite-util.pod
    M doc/pod/tdx-util.pod

  Log Message:
  -----------
  Mention inndf in overview documentation

inndf -n gives the number of stored overview data.