deploy-site: fix plugin install and odoc.support copy
- Install odoc-jon-shell, odoc-interactive-extension, and
odoc-scrollycode-extension instead of x-ocaml (which doesn't need
installing since it's found from _build/install/)
- Fix odoc.support copy to use mkdir -p and glob pattern
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>