docs: Update Contribution Guidelines and Code of Conduct

[panz3r]

Motivation

This PR updates project documentation to improve contribution guidelines and ensure contact information is current.

Description of Changes

• Added a Pull Request (PR) template to enhance contribution guidelines and standardize the PR submission process.
• Updated the community contact email address in the CODE_OF_CONDUCT.md file.

How to Test

1. CI Checks: Verify that all automated tests (Vitest) and build steps pass successfully on this PR. (N/A for documentation-only changes, but good to keep as a standard check)
2. Local Verification (Optional):
   • Review the new PR template file (.github/pull_request_template.md or similar location) to ensure it matches the intended template.
   • Check the CODE_OF_CONDUCT.md file to confirm the email address has been updated correctly.

Checklist

• My code follows the project's style guidelines (N/A for this PR)
• I have added or updated tests to cover the changes (N/A for this PR)
• I have updated relevant documentation
• All tests are passing locally (N/A for this PR)
• CI checks are passing
• I have reviewed my own code and lock file changes (Reviewed documentation changes)
• I have checked for any potential security implications (N/A for this PR)
• I have verified the changes work as expected (Documentation renders correctly)

Notes for Reviewers

This PR primarily focuses on documentation improvements. Please ensure the new PR template is correctly placed for GitHub to recognize it, and verify the email update in the Code of Conduct.