Update copilot-instructions.md

[dannystaple]

No description provided.

[Copilot]

Pull Request Overview

This PR updates the Copilot instructions documentation to streamline the development workflow by removing alternative native npm-based commands and focusing exclusively on Docker-based development. The changes simplify the documentation by removing redundant information and adding new guidance for scripts and utilities.

• Removes all references to alternative native npm workflows
• Adds documentation for the tests/staging directory structure
• Includes new guidance for adding scripts or utilities through Docker Compose

[Copilot]

This guidance is vague and lacks specificity. Consider providing an example of how to run scripts through docker compose or reference existing patterns in the codebase.

Suggested change

	- Ensure these are run through a docker compose command
	- Add new scripts to the `.github/scripts/` directory.
	- To run a script, use a Docker Compose command following the existing pattern. For example, to run a script called `my_script.sh`:
	```bash
	docker compose run base .github/scripts/my_script.sh [arguments]

• Refer to the commands above (e.g., for new_post.sh) for additional patterns.

[github-actions]

🦙 MegaLinter status: ❌ ERROR

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
❌ ACTION	actionlint	5		6	0	0.08s
✅ BASH	bash-exec	1		0	0	0.0s
✅ BASH	shellcheck	1		0	0	0.05s
⚠️ BASH	shfmt	1		1	0	0.0s
❌ C	cppcheck	8		8	0	0.3s
❌ CPP	cppcheck	8		8	0	0.33s
✅ JSON	npm-package-json-lint	yes		no	no	0.47s
✅ JSON	v8r	12		0	0	8.33s
❌ MARKDOWN	markdown-link-check	738		214	0	58.75s
✅ REPOSITORY	gitleaks	yes		no	no	13.7s
✅ REPOSITORY	git_diff	yes		no	no	1.18s
❌ REPOSITORY	grype	yes		2	no	32.54s
✅ REPOSITORY	secretlint	yes		no	no	41.65s
✅ REPOSITORY	syft	yes		no	no	1.52s
✅ REPOSITORY	trivy-sbom	yes		no	no	3.39s
✅ REPOSITORY	trufflehog	yes		no	no	4.89s
✅ XML	xmllint	1		0	0	192.04s
✅ YAML	v8r	13		0	0	6.94s

See detailed report in MegaLinter reports