添加说明

README.md

+# rn-project
+
+# 需要先安装react-native 的基础环境，环境请查看wiki文档前端技术支持
+
+## Project setup
+```
+npm i
+```
+
+### Compiles and hot-reloads for development
+```
+npm run android
+```
+
+### Lints and fixes files
+```
+npm run lint
+```