docs: cover hard-macro builds, macros, bundle.zip, auth scope, and pin tools

[lanserge]

Summary

Updates training docs for five recently merged chipflow-lib PRs.

• #167 BlockPackageDef — new block-package.md walks through hard-macro builds (LEF + Liberty .lib + GDS + blackbox .bb.v stub); chipflow-toml-reference.md gains [chipflow.silicon.block] and "block" as a package option.
• #163 load_blackbox_wrapper — new using-hard-macros.md covers macro consumption: declaring a macro under [chipflow.silicon.macros], instantiating from Python, what travels in bundle.zip, and the NDA vs non-NDA macrostrip workflows.
• #165 bundle.zip submission — training-commands.md now mentions the bundle artifact written next to the RTLIL.
• #166 user:email scope — prereqs and troubleshooting steer users to gh auth refresh -s user:email and explain the silent-drop case (re-auth without the scope).
• #168 chipflow pin swap / pin show — new pin-inspection section plus Quick Reference entries.

Test plan

• Render block-package.md and using-hard-macros.md and confirm the chipflow.toml examples match the lib's Pydantic schemas ([chipflow.silicon.block] width/height; [chipflow.silicon.macros.<name>] blackbox).
• Verify the troubleshooting flow on a fresh GitHub login — gh auth refresh -s user:email resolves the missing_email case.
• Run chipflow pin show / chipflow pin swap on the upcounter to confirm the documented invocation matches the CLI.
• Spot-check a chipflow silicon submit --dry-run writes bundle.zip next to the RTLIL with the documented layout.