Add repo-standardizer skill: polish any GitHub repo surface (#2715)

* Add repo-standardizer skill: polish any GitHub repo surface

* fix(skill): remove non-string metadata and fix template README refs for vally lint

* docs(skill): drop markdown relative links from README language-switcher example

Vally valid-refs flagged ./README.md and ./README.zh.md as missing file
references; they are generated artifacts, not skill files. Keep the
example as plain text to satisfy the linter.

* fix(template): add missing language switcher to English README template

Align with README.zh.md template and SKILL.md switcher convention:
current language as plain text, other languages as relative links.

---------

Co-authored-by: programmingWTF <programmingWTF@users.noreply.github.com>

skills/repo-standardizer/templates/README.zh.md

@@ -0,0 +1,62 @@
+# PROJECT_NAME
+
+< [English](./README.md) | 简体中文 >
+
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
+![GitHub release](https://img.shields.io/github/v/release/OWNER/REPO)
+![GitHub issues](https://img.shields.io/github/issues/OWNER/REPO)
+![GitHub pull requests](https://img.shields.io/github/issues-pr/OWNER/REPO)
+![GitHub stars](https://img.shields.io/github/stars/OWNER/REPO)
+
+> 一句话介绍这个项目。
+
+## ✨ 特性
+
+- 特性一
+- 特性二
+- 特性三
+
+## 🚀 快速开始
+
+### 前置要求
+
+- 工具 A
+- 工具 B
+
+### 安装
+
+```bash
+git clone https://github.com/OWNER/REPO.git
+cd REPO
+# 安装步骤
+```
+
+### 使用
+
+```bash
+# 快速上手命令
+```
+
+## 📖 文档
+
+| 主题 | 位置 |
+|---|---|
+| API 参考 | `docs/api.md` |
+| 架构 | `docs/architecture.md` |
+| 贡献指南 | [CONTRIBUTING.md](CONTRIBUTING.md) |
+| 安全政策 | [SECURITY.md](SECURITY.md) |
+
+## 🧪 测试
+
+```bash
+# 测试命令
+```
+
+## 🤝 贡献
+
+欢迎 PR！参见 [CONTRIBUTING.md](CONTRIBUTING.md)。
+通过 [issue 表单](https://github.com/OWNER/REPO/issues/new/choose) 报告问题。
+
+## 📄 许可证
+
+[MIT](LICENSE) © 2026 OWNER