[WanderLandWalker]

What

Adds README.zh-CN.md — a Simplified Chinese translation of README.md — plus a one-line language switcher at the top of the English README.

Checklist from the template, for this docs-only change:

• Pull request is based on the default branch (3.x at this time)
• Pull request includes tests for any new/updated operations/facts — N/A, no code touched
• Pull request includes documentation for any new/updated operations/facts — N/A, this PR is documentation
• Tests pass (see scripts/dev-test.sh) — N/A, no code touched
• Type checking & code style passes (see scripts/dev-lint.sh) — N/A, no code touched
• Pull request title follows the conventional commits format

Why

pyinfra is widely used by Chinese-speaking ops/SRE teams, but the README (the main entry point to the project) is English-only, and the docs site has no Chinese locale. A translated README lowers the first barrier without touching the docs build.

Scope

• README.zh-CN.md — new file, 1:1 translation of the English README: same structure, same order, all commands, code samples, badge URLs and links left byte-for-byte identical (including the code comment inside the apt.packages example). Only natural-language prose is translated.
• README.md — one added line: [English](README.md) | [简体中文](README.zh-CN.md).

No source code, tests, docs build config or licence text touched.

AI disclosure

Per AI_POLICY.md: the Chinese draft was produced with WorkBuddy AI / Claude, then reviewed and corrected by me line by line. I understand the content and take responsibility for it. Happy to adjust terminology if you prefer otherwise — I glossed operation, inventory and dry run in parentheses at first mention and used Chinese afterwards, but I can keep the English terms throughout instead.

Notes

• The Chinese file opens with a one-line note that the English README is authoritative, so future drift can't mislead readers.
• If you'd rather not carry a translated README in the repo root, or would prefer it under docs/ or in the zensical docs build, tell me and I'll move it.
• I'd like to keep the translation in sync as the README evolves, and I'd be glad to become a regular contributor. If there are areas where help is most welcome (docs, connectors, operations), I'd appreciate a pointer.