Readme.md

[Ijaiswalshivam]

What is the change?

Added the code for 2 Sum Array

Related issue?

closes: #146

Checklist:

Before you create this PR, confirm all the requirements listed below by checking the checkboxes [x]:

• I have followed the Code of Conduct.
• I have checked there aren't other open Pull Requests for the same update/change.
• I have you tested the code before submission.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generates no new warnings.
• I'm (HSOC) Hack-Club-Rait Summer of code '22 Contributor

Screenshots (if any)