Uses submodules to track bril for dependencies brili and bril2json and bril2text.

Nix sets up a venv for the python utils.

./bin/setup.sh should be called to set up bril2json and bril2txt. Unfortunately they are installed to local rust/cargo folders instead of a project .venv, but the python versions were too slow.

nix develop # (or automatic using direnv)
git submodule init && git submodule update
./bin/setup.sh