Solved daily leetcode problem #8 using python.

[Rohit-Sharma-RS]

🚀 What does this PR do?

• Adds solution for LeetCode Daily Challenge on Day 8 in Python.
• Uses concept of stack properly described in the readme

📝 Issue Reference:

Fixes issue: #8

🔧 Solution Details:

• Language Used: Python
• Time Complexity: O(n)
• Space Complexity: O(n)

🌟 Additional Notes (if any):

Beats 92%