feat: add bug report and feature request issue templates; enhance README with contributing guidelines and Copilot instructions

[DanWahlin]

Summary

This PR adds issue templates and enhances the repo's contributor experience:

• Bug report template (.github/ISSUE_TEMPLATE/bug-report.yml) — structured form with chapter dropdown, environment details, and screenshot fields
• Feature request template (.github/ISSUE_TEMPLATE/feature-request.yml) — structured form for proposing new content or improvements
• README updates — enhanced Contributing section with test commands and link to AGENTS.md
• Copilot instructions updates — refined conventions and maintenance matrix

These changes were previously committed directly to main but the push was blocked by a pending CodeQL scan. This PR routes around the branch protection rule.

[Copilot]

Pull request overview

This PR improves the repository’s contributor experience by adding GitHub issue form templates and documenting contribution/Copilot conventions for this courseware repo.

Changes:

• Added GitHub Issue Forms for bug reports and feature requests under .github/ISSUE_TEMPLATE/.
• Added a repository-level .github/copilot-instructions.md describing writing/content/sample-code conventions.
• Updated README.md with an “AI Ready” badge and a new Contributing section.

Show a summary per file

File	Description
README.md	Adds AI Ready badge and a new Contributing section for contributors.
.github/copilot-instructions.md	Introduces repo-specific Copilot guidance, conventions, and a maintenance matrix.
.github/ISSUE_TEMPLATE/feature-request.yml	Adds a structured issue form for feature/content requests.
.github/ISSUE_TEMPLATE/bug-report.yml	Adds a structured issue form for reporting bugs in course content/examples.

Copilot's findings

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• Files reviewed: 4/4 changed files
• Comments generated: 3

[Copilot]

This note says PRs that change existing code can’t be accepted, but the README also says “PRs welcome”. To avoid confusion, clarify what kinds of PRs are accepted (e.g., docs/typos/templates) and what isn’t (changes to exercise code).

Suggested change

	- 🤝 **Want to contribute?** PRs welcome!
	- 📚 **Official Docs:** [GitHub Copilot CLI Documentation](https://docs.github.com/copilot/concepts/agents/about-copilot-cli)
	## Contributing
	> **Note**: The code used in the course is designed to generate specific types of output during reviews, explanations, and debugging so we aren't able to accept PRs that change the existing code.
	**How to contribute:**
	1. Fork this repository and clone it to your machine
	2. Create a feature branch (`git checkout -b my-improvement`)
	3. Make your changes
	- 🤝 **Want to contribute?** Documentation, typo, link-fix, and template PRs are welcome. Please see [Contributing](#contributing) for details.
	- 📚 **Official Docs:** [GitHub Copilot CLI Documentation](https://docs.github.com/copilot/concepts/agents/about-copilot-cli)
	## Contributing
	> **Note**: The code used in the course is designed to generate specific types of output during reviews, explanations, and debugging, so we aren't able to accept PRs that change the existing exercise or course code.
	>
	> We do welcome PRs for non-code improvements such as:
	> - fixing typos or grammar
	> - improving documentation or instructions
	> - correcting broken links
	> - updating templates, metadata, or other repository content that does not change the exercise behavior
	>
	> If you're unsure whether a change is in scope, please open an issue first.
	**How to contribute:**
	1. Fork this repository and clone it to your machine
	2. Create a feature branch (`git checkout -b my-improvement`)
	3. Make your non-code changes