docs: add skill removal instructions to README

README.md

@@ -17,6 +17,20 @@ npx skills add gitea@livebook:images/skills.git --skill runtime-image
 npx skills add gitea@livebook:images/skills.git --skill runtime-image-en
 ```
 
+## 卸载
+
+交互式选择要删除的 skill:
+
+```bash
+npx skills remove
+```
+
+直接删除指定 skill(`-g` 删除用户级安装,即 `~/.agents/skills` 下的):
+
+```bash
+npx skills remove runtime-image -g
+```
+
 ## Skills 列表
 
 | Skill | 语言 | 说明 |