chore: added pull request template

[anks-95]

Overview

• Added pull-request template for better understanding of the PR.

## What: overview about this PR

## Why: the purpose about this PR

## How: how did you implement/fix it?

## Environment Variables:
### Do you add environments variables:
- [ ] what do you want to reviewer to check?  
- [ ] None

### Do you add production environment variables: 
- [ ] what do you want to reviewer to check?
- [ ] None

### Did you wrote Test:
- [ ] Unit test
- [ ] Integration test
- [ ] Manual test

@HarshwardhanPatil07

• As in most of the PR's there weren't proper description of the PR which was quite difficult for reviewer and for others to understand about the PR.
• So this PR just focuses on writing a clear and detailed description of the PR.

This pull request is not intended as a Hacktoberfest contribution.