shared docker volume for downloaders in compose file

See merge request memri/pod!11

Import notes2

See merge request memri/pod!10

- Re-added import make_graph as it is needed for testing

- Notes-importer can now be called through the warp-API

# Conflicts:
#	.gitignore
#	Settings.toml

Some small cleanup (remove newlines and added some rustdoc)

- Tags now also get imported into the database (no link is made with the notes yet though)

Note:
- Code is somewhat heavy on unwrap(), so error handling could/should still be improved
- _query_notes and _simple_example are not yet used, perhaps move them to a separate example crate in the (nearby) future

schema definitions in separate file to enable import from the schema repository (SSOT)

See merge request memri/pod!9

# Conflicts:
#	Cargo.toml
#	src/main.rs

the CI doesn't work anyway right now,
so no need to bother GitLab
with the impossible task.

Audit access log

See merge request !8