Add: tags

Author: Openset

README.md

@@ -7,6 +7,7 @@
 
 # [LeetCode](https://openset.github.io/leetcode)
 LeetCode Problems' Solutions
+[[话题分类](https://github.com/openset/leetcode/blob/master/tag/README.md)]
 
 [![Build Status](https://travis-ci.org/openset/leetcode.svg?branch=master)](https://travis-ci.org/openset/leetcode)
 [![codecov](https://codecov.io/gh/openset/leetcode/branch/master/graph/badge.svg)](https://codecov.io/gh/openset/leetcode)

internal/readme/readme.go

@@ -95,6 +95,7 @@ var format = "<!--|This file generated by command(leetcode %s); DO NOT EDIT.%s|-
 var defaultStr = `
 # [LeetCode](https://openset.github.io/leetcode)
 LeetCode Problems' Solutions
+[[话题分类](https://github.com/openset/leetcode/blob/master/tag/README.md)]
 
 [![Build Status](https://travis-ci.org/openset/leetcode.svg?branch=master)](https://travis-ci.org/openset/leetcode)
 [![codecov](https://codecov.io/gh/openset/leetcode/branch/master/graph/badge.svg)](https://codecov.io/gh/openset/leetcode)