Add N-Queens backtracking solution

[LeanneJacob]

Description

Added a Python implementation of the N-Queens Problem using the backtracking algorithm. The project includes an easy-to-understand README explaining the problem, constraints, backtracking approach, and solution.

• Issue_no: <insert your issue no here>
• Not applicable

Type of change

• New project insert
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Documentation Update

Project

• Your Project Name: N-Queens Problem

• Short Description:

A Python project that solves the N-Queens Problem using backtracking. It places N queens on an N × N chessboard while ensuring that no two queens share the same row, column, or diagonal.

Checklist:

• I have named my files and folder, according to this project's guidelines.
• My code follows the style guidelines of this project.
• I have commented on my code, particularly in hard-to-understand areas.
• I have created a helpful and easy to understand README.md, according to the given README template.
• My changes do not produce any warnings.