chore: Add PR template

[aimurphy]

Thank you for your contribution to the OpenRAG project! 🚀

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• Follow the project structure, style, and dev/test guidelines described in CONTRIBUTING.md.
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• Add or update documentation, if needed.
• Monitor your PR after you submit it, and respond to comments in a timely manner. Inactive PRs can be closed at the maintainers' discretion.

Description

This PR adds a PR template.
This helps contributors submit well-defined PRs, and it expedites the review process by answering basic questions about the changes.

⚠️ IDK if this file is in the right place in the project structure.
⚠️ IDK how to test this.

Related issues

The following issues are related to this PR:

Closes #1150

Type of changes

Select all that apply:

• chore: Chore or trivial change
• docs: Documentation update
• feat: New feature or enhancement
• fix: Bug fix
• perf: Performance improvements
• refactor: Rewrite existing code
• revert: Revert a previously merged change
• style: UX/UI changes
• test, ci, or build: Changes to the project's build, CI/CD, GitHub Actions, tests, etc.

💡The first word in your PR title must match one of the change categories to pass the PR title check.

Breaking changes

Does this PR introduce breaking changes?

• Yes
• No
• Not sure

Tests

Select the tests you ran to verify your changes:

• Unit tests
• Manual testing (please explain)
• Not applicable (ex. documentation changes)
• Other (please explain)

Explanation of tests (if needed):

⚠️ IDK how to test this.

Disclosure of AI-generated code

This section is optional, but it can help set the context for your PR.

Please let us know if your PR contains AI-generated code:

• More than 50% of this PR is AI-generated code (please explain)
• Less than 50% of this PR is AI-generated code (please explain)
• I didn't use AI tools for this PR, or I used trivial assistance like spell check or small in-line suggestions

If your PR contains AI-generated code, please answer the following questions:

• Where is the AI-generated code in your PR? Which files, functions, or lines?
  • Answer: I used Gemini (via Google Search) to remind me how to create a PR template file, and it generated an initial .md outline.
• Did you edit the code after generating it? For example, did you make the code more secure, remove redundancies, or add exception handling?
  • Answer: I rewrote and expanded the template that was generated by Gemini.
• What is your level of proficiency in the code's language (none, beginner, intermediate, advanced, expert)?
  • Answer: Advanced

[mendonk]

Approved