fix(skills): remove phantom resource references and fix CoC links (#447)

Remove references to non-existent resource files (references/, assets/,
scripts/, examples/) from 115 skill SKILL.md files. These sections
pointed to directories and files that were never created, causing
confusion when users install skills.

Also fix broken Code of Conduct links in issue templates to use
absolute GitHub URLs instead of relative paths that 404.

plugins/python-development/skills/python-packaging/SKILL.md

@@ -864,25 +864,3 @@ recursive-exclude * *.py[co]
 - [ ] GitHub repository linked
 - [ ] Tested on TestPyPI first
 - [ ] Git tag created for release
-
-## Resources
-
-- **Python Packaging Guide**: https://packaging.python.org/
-- **PyPI**: https://pypi.org/
-- **TestPyPI**: https://test.pypi.org/
-- **setuptools documentation**: https://setuptools.pypa.io/
-- **build**: https://pypa-build.readthedocs.io/
-- **twine**: https://twine.readthedocs.io/
-
-## Best Practices Summary
-
-1. **Use src/ layout** for cleaner package structure
-2. **Use pyproject.toml** for modern packaging
-3. **Pin build dependencies** in build-system.requires
-4. **Version appropriately** with semantic versioning
-5. **Include all metadata** (classifiers, URLs, etc.)
-6. **Test installation** in clean environments
-7. **Use TestPyPI** before publishing to PyPI
-8. **Document thoroughly** with README and docstrings
-9. **Include LICENSE** file
-10. **Automate publishing** with CI/CD