Update showcase.yml
Adds OSD to showcase
Refactors showcase sub-page metadata rendering
Merge pull request #7 from IIIF/refactor-includes

Refactors showcase sub-page metadata rendering
Merge pull request #6 from IIIF/add-osd-to-showcase

Adds OSD to showcase
Merge pull request #8 from IIIF/master

Deploy OSD and refactored includes