add RAMenPaSTA section in mdbook-katex syntax

[chung-thai-nguyen]

[x] Add mdBook-KaTeX preprocessor for the cookbook which supports Katex (i.e.
support general syntaxes from Latex and markdown in general, more beautiful rendering for math content)
[x] Full description for generic relaxed R1CS, conditional folding, RAMenPaSTA

[chiro-hiro]

The RAMenPaSTA content and mathematical formalism are solid. A few issues need fixing:

Blocking:

1. Citation key case mismatch: {{#cite bcms20}} in chapter.md won't resolve — the key in refs.bib is BCMS20 (uppercase). BibTeX keys are case-sensitive in mdbook-bib. Fix: change to {{#cite BCMS20}}.
2. MathJax + KaTeX conflict: book.toml still has mathjax-support = true alongside [preprocessor.katex]. These two renderers conflict and will corrupt math display across the entire book. Please remove mathjax-support = true from [output.html].

Should fix:
3. Literal \\ in prose: In conditional-folding-scheme.md, proceeds as follows:\\\\ sits outside any math block and will render as literal backslashes. Remove the \\\\.
4. Internal links use .html extension: Links like [#](./generic-relaxed-r1cs.html#...) bypass mdbook's link checker. Use .md paths instead — mdbook rewrites them automatically.

Nit: book.toml is missing a trailing newline.