docs(the-workshop): fix workshop scaffold, bench location, and component list

Address the remaining doc/skill review findings:
- workshop-create: 'gh repo create --clone' clones into the CWD, which
  nests the new repo when run from inside a checkout. Add an explicit
  clone-parent selection + 'rev-parse --is-inside-work-tree' guard, and
  run the create from that parent.
- workshop-create: desks/ and bench/ were scaffolded empty, so Git drops
  them and a later clone loses the scaffold. Scaffold .gitkeep in each
  and commit the placeholders.
- bench-read: make <workshop>/bench/ the primary shared location (the
  directory workshop-create actually establishes) with desk-local
  artifacts as a secondary source, instead of treating the repo root as
  the bench.
- the-workshop README: add the Workshop Create skill to the component
  table so all six packaged components are documented.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 26faf13e-639c-4a21-ac05-c0dc2bff7c62

plugins/the-workshop/README.md

@@ -19,6 +19,7 @@ A **desk** isn't a sub-agent — it's a peer with a history. Sub-agents inherit
 | Type | Name | Description |
 |------|------|-------------|
 | Agent | [Workshop TA](../../agents/workshop-ta.agent.md) | Room coordinator — sees all desks, routes work, tracks state, emits signals |
+| Skill | [Workshop Create](../../skills/workshop-create/) | Create a new workshop — the root where desks live — locally or backed by a new private GitHub repo |
 | Skill | [Desk Open](../../skills/desk-open/) | Create a new desk with journal and folder structure |
 | Skill | [Desk Journal](../../skills/desk-journal/) | Read/write persistent memory across sessions — the cairn trail |
 | Skill | [Signal Write](../../skills/signal-write/) | Emit structured signals: hands-up, blocked, done, checkpoint |