Maximum Subarray

**Is your feature request related to a problem? Please describe.**
Want to add the Maximum Subarray question of LeetCode in the Python Data structure folder

**Describe the solution you'd like**
Problem Statement:
Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

Example 1:

Input: nums = [-2,1,-3,4,-1,2,1,-5,4]
Output: 6
Explanation: [4,-1,2,1] has the largest sum = 6.
Example 2:

Input: nums = [1]
Output: 1
Example 3:

Input: nums = [5,4,-1,7,8]
Output: 23

**Describe alternatives you've considered**
LeetCode question no. 53

**Additional context**
I would like to contribute and work on this issue as a participant of LGM SOC'21 will you please assign it to me

Programming language

### Programming language

- [ ] C
- [ ] C++
- [ ] Java
- [x] Python