v16.8.0

Summary

• Introduce Hooks API (useState, useEffect, useReducer, etc.) with ESLint plugin support for hook linting
• Add strict‑mode double render for Hooks in development, warn on mismatching Hook order, and enforce cleanup functions to return undefined or a function
• Extend React.lazy to accept synchronous thenables, improve bail‑out rendering using Object.is, and provide act() utilities for test renderers