[InterNetNews/inn] 573b8f: Actualize documentation about file descriptors

[Julien ÉLIE]

  Branch: refs/heads/main
  Home:   https://github.com/InterNetNews/inn
  Commit: 573b8f3894a20e565af1ddfd21a2b015dd841e8f
      https://github.com/InterNetNews/inn/commit/573b8f3894a20e565af1ddfd21a2b015dd841e8f
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2023-07-08 (Sat, 08 Jul 2023)

  Changed paths:
    M doc/pod/inn.conf.pod
    M doc/pod/innfeed.conf.pod
    M doc/pod/install.pod

  Log Message:
  -----------
  Actualize documentation about file descriptors

Better explain limits, with a link to the Solaris documentation.
Improve wording and actualize the numbers for current systems.