style: fix 51 issues in additive_functionals

- admon: 4 fixes
- code: 3 fixes
- jax: 2 fixes
- link: 5 fixes
- math: 3 fixes
- writing: 34 fixes

Rules addressed:
- qe-math-001: Prefer UTF-8 unicode for simple parameter mentions, be consistent
- qe-math-002: Use \top for transpose notation
- qe-math-004: Do not use bold face for matrices or vectors
- qe-code-002: Use Unicode symbols for Greek letters in code
- qe-code-002: Use Unicode symbols for Greek letters in code
- qe-code-002: Use Unicode symbols for Greek letters in code
- qe-jax-002: Use NamedTuple for model parameters
- qe-jax-002: Use NamedTuple for model parameters
- qe-link-002: Use doc links for cross-series references
- qe-link-002: Use doc links for cross-series references
- ... and 41 more

Author: github-actions[bot]