Add initial PhotoPrism app config

[lastzero]

trafficstars

Note:

• HTTP port 2342 will be exposed directly. Production environments should use an HTTPS proxy like Traefik in front of PhotoPrism. Since it makes sense to set up a single reverse proxy for all apps (instead of each app running its own proxy), this was left open.
• A random initial admin password should be used instead of a static one.
• If PhotoPrism doesn't start it's typically due to wrong storage folder permissions, like when it was automatically created by Docker as root but the container is running as UID 1000.
• SQLite may be used if MariaDB is too heavy, however it doesn't scale well for many pictures and/or cpu cores.