Collect the sphinx build + live-preview one-liners (incl. the nix
`.#docs` opt-in shell and the `d2` diagram specifics) so
contributors don't have to reverse-engineer them,
- new `notes_to_self/howtodocs.md` terse cheat-sheet (force-added
past the `notes_to_self/` ignore, same as `howtorelease.md`),
- a rendered "Building these docs" section in the dev-tips guide
(`docs/project/dev-tips.rst`),
- a README pointer to the note.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi