docs: use npx skills add for skill installation

Replace curl command with `npx skills add ant-design/ant-design-pro`
in both cheatsheets.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docs/cheatsheet.en-US.md

@@ -495,8 +495,7 @@ Create a file in `src/models/` exporting a custom Hook, then use `useModel('file
 **Q: How to upgrade the project?**
 First, install the pro-upgrade skill into your project:
 ```bash
-mkdir -p .claude/skills/pro-upgrade
-curl -sL https://raw.githubusercontent.com/ant-design/ant-design-pro/master/.claude/skills/pro-upgrade/SKILL.md -o .claude/skills/pro-upgrade/SKILL.md
+npx skills add ant-design/ant-design-pro
 ```
 Then run `/pro-upgrade` in Claude Code at the project root — AI will auto-diff the latest template and upgrade your project (deps, config, code patterns, etc.). For other AI assistants, paste the content of `.claude/skills/pro-upgrade/SKILL.md` to them.
 

docs/cheatsheet.zh-CN.md

@@ -495,8 +495,7 @@ export default {
 **Q: 如何升级项目？**
 先将 pro-upgrade skill 安装到项目中：
 ```bash
-mkdir -p .claude/skills/pro-upgrade
-curl -sL https://raw.githubusercontent.com/ant-design/ant-design-pro/master/.claude/skills/pro-upgrade/SKILL.md -o .claude/skills/pro-upgrade/SKILL.md
+npx skills add ant-design/ant-design-pro
 ```
 然后在项目根目录用 Claude Code 运行 `/pro-upgrade`，AI 会自动对比最新模板并完成升级（依赖、配置、代码模式等）。如使用其他 AI 助手，可将 `.claude/skills/pro-upgrade/SKILL.md` 中的内容提供给它。