Added about postman challenge in README.md

[shravya312]

📥 Pull Request

Description

Added about postman challenge in README.md

Fixes #1327

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

Thank you for submitting your pull request! 🙌 We'll review it as soon as possible.). If there are any specific instructions or feedback regarding your PR, we'll provide them here. Thanks again for your contribution! 😊

[github-actions]

⚡️ Lighthouse Report for the Deploy Preview of this PR 🚀

🔗 Site: Algo | Live Site

URL 🌐	Performance	Accessibility	Best Practices	SEO	📊
/algo/	🟡 58	🟢 96	🟡 71	🟡 86	📄
/algo/docs	🔴 47	🟢 96	🟡 75	🟢 100	📄
/algo/blog	🟡 67	🟢 92	🟢 96	🟡 86	📄

[ajay-dhangar]

Done

[github-actions]

🎉🎉 Thank you for your contribution! Your PR #1916 has been merged! 🎉🎉