[mnriem]

Description

Move the extension development guide to docs/extensions/developing.md and publish it as Developing extensions alongside the extension overview and publishing guide.

Use GitHub Copilot's default skills syntax throughout the examples, retaining dotted manifest identifiers and portable command-reference tokens. Link to the shared command invocation reference for other integrations instead of duplicating syntax guidance.

Update navigation, incoming links, relative documentation links, and the existing hook-documentation test path.

Testing

• Tested locally with uv run specify --help
• Ran existing tests with uv sync && uv run pytest
• Tested with a sample project (if applicable)

The checklist's exact CLI/full-suite commands and sample-project test were not run; this change updates documentation and an existing documentation-test path.

• .venv/bin/python -m pytest tests/extensions/bug/test_bug_hooks.py -q — passed, 19 tests.
• cd docs && docfx docfx.json — passed with 3 warnings: two existing parent-directory glob warnings and an unrelated link warning in reference/core.md.
• git diff --check — passed.
• Served the generated site locally and confirmed the relocated guide returns HTTP 200.

AI Disclosure

• I did not use AI assistance for this contribution
• I did use AI assistance (fill in the disclosure below)

AI disclosure: GitHub Copilot App, powered by GPT-6.1 Sol (gpt-6.1-sol), prepared the documentation changes, updated the existing test path, ran focused checks, and authored the commit and PR on behalf of @mnriem. Execution was autonomous with human-directed scope and iterative documentation feedback; no claim of human line-by-line review is made. Reasoning-effort setting was not exposed.

[Copilot]

🟢 Approval recommended

No active review issues remain, and the noted documentation suggestions are non-blocking.

No open issues 🎉

What changed in this PR

This documentation-only pull request relocates and publishes the extension development guide on the DocFX site, updates related links and navigation, and aligns examples with GitHub Copilot’s default skills layout.

Changes:

• Publishes docs/extensions/developing.md alongside the extension overview and publishing guides.
• Updates navigation and incoming documentation links.
• Revises Copilot skills examples and shared command-reference guidance.
• Updates the hook-documentation test for the relocated guide.

File	Summary	Review notes
tests/​extensions/​bug/​test_bug_hooks.py	Updates the documentation-test path for the relocated guide.	No final comments.
extensions/​template/​README.md	Updates the template’s development-guide link.	No final comments.
extensions/​README.md	Updates the incoming development-guide link.	No final comments.
docs/​toc.yml	Adds the developing guide to Extensions navigation.	Nit, 1 vote: Use Developing extensions as the navigation label.
docs/​extensions/​publishing.md	Links to the relocated development guide.	No final comments.
docs/​extensions/​overview.md	Links users to the relocated development guide and shared reference.	No final comments.
docs/​extensions/​developing.md	Provides the revised extension development guidance and Copilot skills examples.	Moderate, 1 vote: Document the integration switch copilot --integration-options="--skills" path or explain the --force/default-integration trade-off for existing projects.
.github/​ISSUE_TEMPLATE/​config.yml	Updates the issue-template contact link to the published guide.	No final comments.

_{Review effort: Lite (auto)}