Tasks are Done

[MohitHereVats]

What did you do?

1)Implemented the string calculator logic with comprehensive TDD test coverage in stringCalculator.ts and stringCalculator.test.ts.
2) Fixed all accessibility issues in [App.tsx]:
-- Added descriptive alt text to the image.
-- Improved color contrast for all text and UI elements.
-- Corrected heading hierarchy and removed inline font size from headings.
-- Added a proper label for the textarea input.
-- Converted the calculate action to a semantic with accessible labeling.
-- Ensured focus indicators are visible for keyboard navigation.
-- Used ARIA live regions for result and error messages.
-- Cleaned up code and improved layout for better accessibility and usability.
-- Added [App.css] for accessibility and focus styles.

Why did you do it?

1. The string calculator logic and tests were missing and required for the assignment.
2. The UI had multiple accessibility issues that needed to be resolved to meet WCAG and best practices.
3. Improved usability for all users, including those using screen readers and keyboard navigation.
4. Ensured the project meets the requirements outlined in the README.