Added Tkinter calculator

[anuradha8055]

Description

This PR adds a beginner-friendly GUI calculator built using Python's Tkinter library. It supports basic arithmetic operations like addition, subtraction, multiplication, and division, and features a clean, responsive layout.

Fixes #396

• [ x] Issue_no: 396
• Not applicable

Type of change

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

Project

our Project Name: tkinter GUI calculator

A simple calculator application built using Tkinter. It allows users to perform basic operations through a graphical interface. The layout is intuitive and beginner-friendly, making it ideal for learning GUI development in Python.

Checklist:

Please tick all the boxes that are fulfilled by your Pull Request.

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

[anuradha8055]

Hi, I've submitted the PR for review. Please let me know if any changes are needed. Thanks!