Added TwoPointersAlgo.java

[varunvjha]

This is an algorithm which reduces the time complexity while finding all pairs in an array that sum up to a given number.

Description

Related Issue

This PR closes #

Motivation and Context

Screenshots (if any)

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.

[SVijayB]

Thanks for PR! Merged 👍

[varunvjha]

@SVijayB Could you please mention one of the topics in your Repo as "hacktoberfest-accepted"

[SVijayB]

@varunvjha if the pull request is merged into a repository with the label hacktoberfest, it is automatically considered towards progress.