release: prepare v0.1.4 — hosted demo live, docs overhaul, bump package versions

[Zhang-JiahangH]

Motivation

• Publish a v0.1.4 release that announces the hosted demo and updates workspace package versions.
• Improve documentation discoverability by reorganizing README content so API, benchmark, and demo are more prominent for humans and AI crawlers.
• Keep the package-level README in sync so npm consumers see the same concise usage and links.

Description

• Added a 0.1.4 entry to CHANGELOG.md that documents the hosted demo URL https://www.zhangjiahang.com/react-virtualized-diff and high-level release notes.
• Bumped version to 0.1.4 in packages/react/package.json, apps/demo/package.json, and apps/benchmark/package.json.
• Rewrote the root README.md and README.zh-CN.md to surface API, Benchmark, and Demo sections with a clearer, search-friendly structure and added a quick API table.
• Updated packages/react/README.md to provide concise install/usage instructions, demo/changelog links, and an API summary for npm consumers.

Testing

• Ran pnpm -r typecheck; packages/react typecheck completed but apps/benchmark typecheck failed with TS2688: Cannot find type definition file for 'vite/client'.
• Attempted pnpm install in the environment but the install failed with a 403 Forbidden while fetching registry packages (no registry auth token available), so full install/CI verification could not be completed.
• No additional automated tests were present in the workspace to run (test scripts are placeholders), so validation is limited to the above typecheck/install attempts.

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Codex Task