[docs] Auto-formatting the doc

Hi, Are there some tools to auto-format the doc? Something similar to flake8, black, that would allow to call "make format" and get the documentation formatted. Or at least would ensure that I get warning if a documentation PR do not follow the norm. I was checking whether doctest was doing what I want, but doctest failed (see https://bugs.python.org/issue45920 for the report about it). `make check` accepted my code even when it had lines that were more than 80 chars long without need for it