Added the Python solution of Leetcode-daily Challenge and readme file explaining the code

[Anshikapal05]

🚀 What does this PR do?

• Adds solution for LeetCode Daily Challenge on (Monday 07/10/2024) in (Python).
• This problem involves reducing a string by repeatedly removing the substrings "AB" or "CD" whenever they appear. The goal is to find the minimum possible length of the string after all such removals. Used a stack to simulate the removals

📝 Issue Reference:

Fixes issue: # 7

🔍 Checklist:

Please ensure the following before submitting your PR:

• [x] I have placed my solution in the correct folder (solutions/day07/).
• [x] My code follows clean coding practices and is efficient.
• [x] I have added comments in my code to explain the approach.
• [x] I have updated the README.md for the specific day with a brief explanation of my solution.
• [x] I have tested the solution on LeetCode and it works correctly.

🔧 Solution Details:

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

🌟 Additional Notes (if any):

[arya2004]

looks good to me @Anshikapal05