Create design doc about an open backend like nostr or matrix

[friedger]

Currently, the backend (database, edge function) are hosted on supabase, a closed system that is defined by hierachical permissions.

Can we use an open backend?
Like nostr? Or Matrix?

How would that look like? Which data can/shall be posted online?

[friedger]

Implementation using nostr:

• restrict nostr.commonshub.brussels to be private
• use public/private key for the server
• booking properties, like date, title, etc. are tags in the nostr message
• approval is emoji

Booking request sent by email should be encrypted messages