Resolve "Prepare backend for move to postgres"

.dockerignore

.gitignore

build/Dockerfile

build/Dockerfile.dev

build/be-dev-compose.yml

build/be-prod-compose.yml

build/db-dev-compose.yml

dev/README.md

dev/init.sh

dev/seed-db.sh

dev/seed.py

exercise/migrations/0005_auto_20240625_1241.py

exercise/models.py

exercise_definition/lib/definition_validator.py

exercise_definition/lib/validation/common.py

exercise_definition/lib/validation/learning_objectives.py

exercise_definition/lib/validation/questionnaires.py

exercise_definition/migrations/0004_auto_20240625_1239.py

exercise_definition/models/models.py

poetry.lock