ci: Add markdown template for PRs

[fvanderflier]

What Changed?

• Added a PR template to ease documenting changes and ease up reviews.

Why?

Explain why these changes were needed. What problem does this solve? Link any related issues.

Fixes #246

Type of Change

Check the box that applies by putting an 'x' inside the brackets: [x]

• 🐛 Bug fix (fixes an issue without breaking existing functionality)
• ✨ New feature (adds new functionality without breaking existing features)
• 💥 Breaking change (existing functionality will be affected)
• 📝 Documentation update
• 🔧 Maintenance (refactoring, dependencies, configuration)

How Did You Test This?

Describe what you did to verify your changes work correctly. This helps reviewers understand how to test your PR.

What I tested:

• Running this PR with an empty description

How to test it:
Optional: Add steps for reviewers to reproduce your testing
1.
2.

Review Checklist

• My code follows the project's style and conventions
  Quick self-check before submitting. You don't need to check every box, but consider each item.
• I've updated relevant documentation (if needed)
• I've tested my changes and they work as expected

Screenshots / Additional Context

Optional: Add screenshots, logs, or any other helpful information for reviewers