[docs] [issue32124] Document functions safe to be called before Py_Initialize()

Eric Snow <ericsnowcurrently@gmail.com> added the comment: I've left a review (writing it as you merged the PR). My main concern is that we not promise more than we must. Every pre-init function or variable we promise to embedders represents global state that is hard to get rid of. It also entrenches pre-init API and state that we're aiming to deprecate (via PEP 432). ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue32124> _______________________________________