Create template.md

[AkanshaMundel]

creating template file so that any contributor must go through before creating pr

Description

added some guidelines for contributors

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.
• [x ] I have updated the documentation accordingly.
• [x ] I have read the CONTRIBUTING document.