Draft: Demo multiple tags

Crudely add tagged versions to /en.

For this MR job

root index: https://uis.uniofcam.dev/-/devops/experiments/ek-599-guidebook/-/jobs/1579441/artifacts/public/index.html

index for tag at /en/0.1.0 https://uis.uniofcam.dev/-/devops/experiments/ek-599-guidebook/-/jobs/1579441/artifacts/public/en/0.1.0/index.html