fix: include examples README in wheel package (#226)

[EMPLORES]

Summary

Fixes #226(Phase A)Ship the examples index with the wheel so skillware examples and skillware list --examples can work for pip-only installs without relying on GitHub raw access.

Changes

• Copy examples/README.md to skillware/resources/examples/README.md during the build.
• Register the custom build_py command in pyproject.toml.
• Update _examples_readme_path() to check the packaged copy before checkout/cwd discovery and GitHub fallback.

Verification

• python -m build --wheel
• Installed the built wheel into an isolated directory.
• Ran python -m skillware examples outside the repository.
• Ran python -m skillware list --examples.
• Verified that the packaged README is discovered through package resources.

[rosspeili]

Hi @EMPLORES, the approach is on the right track yet a few technical blockers before this is ready to merge:

1. Resolution Order: Per [Feat]: Ship examples/README.md in wheel; optional skillware examples --sync fallback #226, the resolution order must be local checkout → wheel bundled index → GitHub raw. Currently, the packaged resource check runs before the local checkout walk, which breaks live editing in local checkouts / editable installs.
2. Source Distribution (sdist) Bug: examples/README.md was not added to MANIFEST.in. When building from an sdist archive, examples/ won't exist in the tarball, causing build_hooks.py to raise FileNotFoundError. Please add include examples/README.md to MANIFEST.in.
3. Packaging Simplicity: Consider avoiding [tool.setuptools.cmdclass] / build_hooks.py if possible in favor of standard declarative package-data / MANIFEST.in to prevent build-isolation edge cases.
4. Missing Tests & Docs:
   • Add unit test coverage in tests/test_cli.py verifying that the bundled resource is resolved when local files are absent.
   • Update docs/usage/cli.md mentioning offline bundled examples index support.
   • Add an entry under ## [Unreleased] in CHANGELOG.md.

Please update the PR with these fixes so we can get this merged cleanly!