Update README_CN.md

PrincessGod · web-flow · commit 165af85a2108 · 2018-01-08T23:38:44.000+08:00
diff --git a/README_CN.md b/README_CN.md
@@ -12,7 +12,7 @@
 确保已经安装 [Node](https://nodejs.org/en/) , 然后
 
 ```
-npm install obj23dtiles
+npm install -g obj23dtiles
 ```
 
 ### 基本用法
