Update README.md

Author: MrWangJustToDo

README.md

@@ -6,4 +6,16 @@ DevTools for @my-react project, currently in beta.
 
 ![screen shout](dark.png)
 
-![screen shout](setting.png)
+![screen shout](setting.png)
+
+## Build & Install
+
+```shell
+pnpm install
+
+pnpm run build:packages
+
+pnpm run build:extension
+
+# load the `chrome/out` dir via `chrome extension`
+```