Bring CircuitGen Generator documentation in line with the shared CircuitGen
layout: changelog, extended CodeStyle, and updated doc hubs in ru/en.

- Add docs/ru|en/CHANGELOG.md (v0.1.0-alpha through v1.3.0, Unreleased) and
  refresh docs index, README, Versioning, and FUNCTIONALITY cross-links.
- Expand CodeStyle (including Doxygen rules) and keep ru/en in sync.
- Normalize “See also” sections in functionality guides.
- Fix GraphPtr wording and typos in ru/NewGenerator.md.
- Remove obsolete root CHANGELOG.md redirect.