Improve pr template format

[kbonney]

Summary

• Summarize changes, including issues that are resolved by this pull request

This PR improves the PR template:

• Instructions moved to comments to reduce boilerplate
• AI disclosure given two checkbox options to help clarify what to do in each case
• Added acknowledgement checkbox

Tests and documentation

• Describe tests and documentation for new features

AI Disclosure

If you submit code generated using AI tools:

• Disclose the AI tools that were used (e.g., GitHub Copilot, ChatGPT)
• Describe the use of AI (e.g., generate concept/idea, code generation, code refactoring, documentation generation, code test generation)

Acknowledgement

By contributing to WNTR, I acknowledge that I have reviewed the software quality assurance guidelines and agree to the following terms and conditions for my contribution:

1. I agree that my contributions are submitted under the Revised BSD License.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.
3. If code was generated using AI tools, I have disclosed the use of AI and reviewed all code for quality assurance, correctness, security, and licensing.

[coveralls]

coverage: 85.832% (+0.05%) from 85.786% — pr-template-update into main