Merge branch 'cleaning' into 'main'

.gitlab-ci.yml

PLANNING.md

README.md

book/book.toml

book/src/SUMMARY.md

book/src/bases1.md

book/src/bases2.md

book/src/cli.md

book/src/closures.md

book/src/collections.md

book/src/gen_types_composes.md

book/src/gestion_erreurs.md

book/src/iterateurs.md

book/src/modules_visibilite.md

book/src/part09.md

book/src/part11.md

book/src/propriete.md

book/src/tooling.md

book/src/types_avances.md

book/src/unsafe.md