Update contribution guidelines and templates

[Kyome22]

Context of Contribution

• Bug Fix
• Refactoring
• New Feature
• Others

Summary of the Proposal

Updates the contribution guidelines and the issue / pull request templates to make expectations around contributing clearer.

• Added a Responding to Review Comments subsection to CONTRIBUTING.md:
  • Do not click Resolve conversation unless you are the reviewer, since only the reviewer can judge whether the issue is actually resolved.
  • Address each review comment individually rather than bundling responses, since larger diffs make it harder for the reviewer to evaluate the change.
• Added an I have read the CONTRIBUTING.md and agree to follow it required checklist item to:
  • .github/pull_request_template.md
  • .github/ISSUE_TEMPLATE/bug_report.yml
  • .github/ISSUE_TEMPLATE/feature_request.yml

Reason for the new feature

N/A (documentation / template change).

Checklist

• I have read the CONTRIBUTING.md and agree to follow it.
• This PR does not contain commits of multiple contexts.
• Code follows proper indentation and naming conventions.
• Implemented using only APIs that can be submitted to the Microsoft Store.
• Works correctly in both dark theme and light theme.
• Works correctly on any device.

🤖 Generated with Claude Code

[mor39a]

LGTM