Web: Support HTML export

[F30]

After the CTF, you want to keep the website around but not have an (at some point outdated) Django instance running. Instead, it should just be served as static HTML.

I currently use a wget command like this for that purpose:

wget --recursive --domains <year>.faustctf.net --page-requisites https://<year>.faustctf.net/

This works, but is hacky and does not include not linked-to files such as the scoreboard JSON.

Ideally, such functionality could be implemented through Django as a special custom command in manage.py or so.