[0.5.2] - 2026-06-22

[jiro-iwanaga]

Documentation, slides, and images only; no library code or public API changes.

Added

• Introductory slides under slides/: rfscorer_overview_en.pdf / rfscorer_overview_ja.pdf
  (distributed under CC BY 4.0), with a new Slides / 紹介スライド section in the README that links
  to each PDF via a cover thumbnail. The editable PowerPoint sources
  (rfscorer_overview_en.pptx / _ja.pptx) are kept locally but git-ignored.
• README images:
  • img/slide_cover_en.png / img/slide_cover_ja.png: slide cover thumbnails used in the Slides
    section.
  • img/recommendation_system_architecture_using_rfscoring_en.png / _ja.png: a recommendation
    system architecture diagram embedded in the README intro.

Changed

• README overhaul (English and Japanese sections aligned):
  • Intro rewritten to explain the recency and frequency signals individually and to walk
    through concrete by-frequency / by-recency / trade-off comparison examples motivating the
    optimization-based scoring; added an inline note citing the source paper.
  • Features converted from a bullet list to a table and reframed: "Calibration-free" → "Stable
    probability estimation", plus new "Downstream use" and "Rich diagnostics & visualization" rows.
  • References and Citation sections collapsed into <details> toggles.
  • Anchor links to the cross-language README lowercased (#rfscorer / #rfscorer-日本語readme).
• docs/repository-structure.md: documented the new slides/ directory (PDF distribution +
  PPTX sources) and expanded the img/ description to cover the architecture diagrams and slide
  thumbnails.
• .gitignore: ignore the slide PPTX edit sources (slides/rfscorer_overview_*.pptx).