docs(cndocs): sync intro-react and network with upstream (#1030)

- intro-react.md: major rewrite to match upstream restructuring
  - Remove class component tabs/examples (EN dropped them)
  - Remove redundant `import React from 'react'` from all examples
  - Update React URLs: reactjs.org → react.dev
  - jsx → tsx code fences
  - Add JS/TS SnackPlayer tabs (matching EN)
  - Update tab groupId/defaultValue to match EN conventions
- network.md: minor sync
  - Fix axios URL: mzabriskie/axios → axios/axios
  - Remove extra jQuery warning text (EN removed it)
  - tsx → ts code fences to match EN

Author: sunnylqm