With part of the goal of moving to GitHub being to minimize how much infrastructure we have to run, one of the long-term goals I have is to use Read the Docs to host Python's documentation. But to get there we have to move any "special" docs over first. That means relocating the devguide (it also means relocating the PEPs, but that's another issue and is blocked first and foremost by https://github.com/python/peps/issues/4).
Thanks to the work of various people we have https://cpython-devguide.readthedocs.io/ so the toolchain for building the devguide on RTFD is done. That means the next step is deciding on a subdomain on the python.org domain to host the docs from. If you have an opinion, go to https://github.com/python/core-workflow/issues/4 and leave a reaction on the appropriate message.