docker compose build
docker compose upGo to http://locahost:8000
docker compose run --rm sphinx make gettext
docker compose run --rm sphinx /home/sphinx/.local/bin/sphinx-intl update -p _build/locale -l frThen translate each .po file with PoEdit. And build your documentation with:
docker compose run --rm sphinx make -e SPHINXOPTS="-D language='fr'" html