Learn nextjs

Ранее указанная ссылка вела на 404.
Добавил актуальную ссылку на CSS модули.

Update css-styling.md

...gment> and escaping angle brackets

...with-jsx.md by correcting fragment syntax to ensure proper rendering.

... quiz example file, along with related plugin and requirement updates.

...r actor models, transitions, and state management, and restructure existing content for clarity and organization.

...mentation path.

...ation files

...aging lists, event capture phase, and clarifying Redux glossary terms. Update links and improve formatting for consistency across multiple files.

...ation path, and modify CSS version. Remove Solid and Python 3 links from index.md for content cleanup.