Add Documentation & Performance Issue Templates + PR Template

[Kavlin-Kaur]

📝 Description

Currently, our repository has limited issue templates.
To improve clarity and maintain consistency, I would like to add the following:

documentation.md – for documentation-related issues.

performance.md – for performance-related issues.

Pull Request Template – to standardize PR submissions.

✅ Tasks

Create documentation.md under .github/ISSUE_TEMPLATE/.

Create performance.md under .github/ISSUE_TEMPLATE/.

Add a PR template in .github/pull_request_template.md.

🎯 Goal

This will make it easier for contributors to raise issues and create PRs in a structured manner.

[devanshu-puri]

hey i am Devanshu , Gssoc contributor and i would like to do this task , please assign me

[Kavlin-Kaur]

I've already done this for PR @devanshu-puri