Adds an agentic (gh-aw) workflow that mirrors the multi-harness workshop
from github-samples/copilot-workshops into the Learning Hub, plus the
Starlight infrastructure it needs: GitHub-admonition rendering, i18n
locales with English at the site root, and a language picker that only
appears when a page has a non-English translation.
Copilot-Session: 9e1d1a4c-a422-4cae-8ea7-b3d5171f58e3
Co-authored-by: GeekTrainer <GeekTrainer@users.noreply.github.com>
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Christopher Harrison