Update README

Author: halfrost

README.md

@@ -24,10 +24,11 @@
 <img src="https://travis-ci.org/halfrost/LeetCode-Go.svg?branch=master">
 </p>
 
-支持 Progressive Web Apps 的题解电子书《LeetCode Cookbook》 <a href="https://books.halfrost.com/leetcode/" rel="nofollow">Online Reading</a>
+支持 Progressive Web Apps 和 Dark Mode 的题解电子书《LeetCode Cookbook》 <a href="https://books.halfrost.com/leetcode/" rel="nofollow">Online Reading</a>
 
 <p align='center'>
-<a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_Safari.png"></a>
+<a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_Safari_0.png"></a>
+<a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_Chrome_PWA.png"></a>
 </p>
 
 离线版本的电子书《LeetCode Cookbook》PDF <a href="https://github.com/halfrost/LeetCode-Go/releases/" rel="nofollow">Download here</a>
@@ -40,8 +41,8 @@
 
 <p align='center'>
 <a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_PWA_iPad.png"></a>
-<a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_PWA_iPad_example1.png"></a>
-<a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_PWA_iPad_example2.png"></a>
+<a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_PWA_iPad_example1__.png"></a>
+<a href="https://books.halfrost.com/leetcode/"><img src="https://img.halfrost.com/Leetcode/Cookbook_PWA_iPad_example2__.png"></a>
 </p>