The policy lived only as prose inside the website's Astro page, so it was
the one user-facing document with no review, no history here, and no way
to change it alongside the code that makes it true.
docs/PRIVACY.md is now that text, transcribed from the published page so
the wording is unchanged, and it becomes the source: the site's build
checks this repository out beside itself and renders this file through an
Astro content collection rather than keeping its own copy. One copy of the
policy exists anywhere, so the two cannot drift.
The README links it from Documentation and gains a Privacy section beside
License. Agendula is being set up the same way.
