New Chapter for admin tasks OPNSense

[cweikl]

New Chapter Administration -> OPNsense admin tasks ->

• logrotate
• check fw logs
• updates
• solutions for:
• time setting problems
• captive portal
• hdd running out of space
• ...
  see: https://ask.linuxmuster.net/t/namensaufloesung-funktioniert-ploetzlich-nicht-mehr/10442/8