Add AIO example compose file

[ASTRELION]

Adds an example docker-compose for using Nextcloud AIO.

Notable considerations for AIO are:

• You need to mount a volume that doesn't exist until AIO creates it (nextcloud_aio_nextcloud), so it has to be defined in the volumes section.
• You must use the container names that AIO creates for hosts, and the ports they use for their services.
• It must share a network with the nextcloud service.
• nextcloud_aio_nextcloud is mounted for the config directory, and in a slightly different place (/nextcloud instead of /nextcloud/config)

I got the relevant ports from netstat from within the containers. 5432 for the database seems to be defined here: https://github.com/nextcloud/all-in-one/blob/main/Containers/postgresql/start.sh#L134. 9000 for web seems to be defined here: https://github.com/nextcloud/all-in-one/blob/main/Containers/nextcloud/entrypoint.sh#L665 (nextcloud-aio-nextcloud:9000 is also referenced in various places for healthchecks and whatnot).

Ref #74