The rustdoc in this toolchain does not parse math (its pulldown-cmark options
omit ENABLE_MATH, `--mathjax` and `html_mathjax` are gone, and a `$$...$$`
paragraph is emitted verbatim). Display formulas were therefore written as
```text code blocks, which the request asked to replace with math syntax.
MathJax 3.2.2 (tex-svg-full, Apache-2.0) is vendored under
docs/vendor/mathjax so the rendered pages need no network access.
docs/mathjax.html loads it from the documentation root computed from rustdoc's
own static file prefix; crates/apsis-rs/build.rs copies it into that root, and
scripts/build-docs.sh makes the copy reliable. Each formula is wrapped in a
raw HTML `<div>` so the markdown layer leaves the LaTeX untouched, because
markdown would otherwise consume the backslashes in `\\\\`, `\,`, `\!` and
`\_`.
All 54 formula blocks (27 formulas, English and Chinese) become `$$...$$`;
the 22 command, 2 diagram and 2 scenario-format blocks stay as ```text.