modify name to twoSum and readme

Author: xingming

README.md

@@ -404,7 +404,7 @@ LeetCode
 |4|[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/)| [C++](./algorithms/cpp/medianOfTwoSortedArrays/medianOfTwoSortedArrays.cpp)|Hard|
 |3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)| [C++](./algorithms/cpp/longestSubstringWithoutRepeatingCharacters/longestSubstringWithoutRepeatingCharacters.cpp)|Medium|
 |2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)| [C++](./algorithms/cpp/addTwoNumbers/addTwoNumbers.cpp)|Medium|
-|1|[Two Sum](https://leetcode.com/problems/two-sum/)| [C++](./algorithms/cpp/twoSum/twoSum.cpp)|Easy|
+|1|[Two Sum](https://leetcode.com/problems/two-sum/)| [C++](./algorithms/cpp/twoSum/twoSum.cpp)[Go](./algorithms/golang/twoSum/twoSum.cpp)|Easy|
 
 
 ### LeetCode Shell

algorithms/golang/addTwoNumbers/addTwoNumbers.go algorithms/golang/twoSum/twoSum.go

@@ -1,4 +1,4 @@
-package addTwoNumbers
+package twoSum
 
 func twoSum(nums []int, target int) []int {
 	numMap := make(map[int]int)