Make IIIFInfo#Versions appear in doc
Make IIIFInfo#Versions appear in doc

For whatever reasons, the possible values of `Versions` did not appear
in the built docs.

oterral/ol3,adube/ol3,tschaub/ol3,adube/ol3,openlayers/openlayers,adube/ol3,geekdenz/openlayers,oterral/ol3,ahocevar/ol3,openlayers/openlayers,geekdenz/openlayers,stweil/ol3,oterral/ol3,bjornharrtell/ol3,ahocevar/ol3,geekdenz/ol3,stweil/openlayers,tschaub/ol3,stweil/openlayers,ahocevar/ol3,tschaub/ol3,stweil/ol3,ahocevar/openlayers,geekdenz/ol3,tschaub/ol3,ahocevar/ol3,stweil/ol3,ahocevar/openlayers,geekdenz/ol3,stweil/openlayers,geekdenz/openlayers,bjornharrtell/ol3,openlayers/openlayers,stweil/ol3,geekdenz/ol3,bjornharrtell/ol3,ahocevar/openlayers