HaoZeke/doxyYoda: doxyYoda action v0.1.1

Added CSS Grid layout for modern page structure Dark mode support with Solarized Dark palette Foldable/collapsible code blocks MathJax 3 integration Demo site with full-featured C++ showcase (demo/) SCSS build pipeline via dart-sass pixi-based task runner (pixi run build, pixi run demo, etc.) GitHub Actions CI and Pages deployment Release tarball task (pixi run release) Reusable GitHub Action (uses: HaoZeke/doxyYoda@v0.1.0) with optional cppreference tag download Version management via tbump (pixi run bump) CHANGELOG.md GitHub Actions release workflow (auto-creates GitHub Release on v* tags) Changed Complete SCSS rewrite: variables, colors, typography, layout, navigation Updated for Doxygen >= 1.12 compatibility Switched from jQuery inline-style hacks to proper CSS overrides CI and Pages workflows now use pixi for reproducible doxygen/sass versions Fixed Dark mode toggle not working for users with OS-level dark mode preference Removed jQuery-based header manipulation mkRel.sh (superseded by pixi run release)