Update index.md

Author: vainfeng

docs/index.md

@@ -48,6 +48,7 @@ dependencies {
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.READ_PHONE_STATE" />
+<uses-permission android:name="android.permission.VIBRATE" />
 ```