Add missing application tutorials

Double check the list of tutorials already published and prepare the ones that are missing.

https://docs.nmaas.eu/nmaas-applications/tutorials/oxidized/

• Adminer
• Bastion Web server
• CTFd
• Healthchecks
• Maat
• N8n
• JuiceShop
• PostgreSQL
• Prometheus Blackbox Exporter
• Telegraf

vlab instance:

• VS Code Server
• Moodle
• UnrealIRC
• Valkey
• Znunny