docs: add changelog by tags and documentation index updates

Слиты Зунин Владимир Викторович запросил слияние docs/changelog-and-guides в main

Move changelog to docs/ru and docs/en with release history from v0.1.0-alpha through v1.3.0. Link FUNCTIONALITY, json, NewGenerator, and GeneratorsPrefixes in doc hubs and README files.

Co-authored-by: Cursor cursoragent@cursor.com