Update the 'image' property description
Update the 'image' property description

We now describe that the image property has a range of both URL and
ImageObject, allowing for more flexible usage of the property.

Fixes #99.

Signed-off-by: Dan Scott <2591e5f46f28d303f9dc027d475a5c60d8dea17a@coffeecode.net>

twcctz500000/schemaorg,dbs/schemaorg,dbs/schemaorg,mortizbank/schemaorg,mortizbank/schemaorg,vemmaverve/schemaorg,mfhepp/schemaorg,ya7lelkom/schemaorg,callahanchris/schemaorg,schemaorg/schemaorg,ya7lelkom/schemaorg,hschema/schemaorg,twcctz500000/schemaorg,ynh/schemaorg,vholland/schemaorg,pwz3n0/schemaorg,haonaturel/schemaorg,twamarc/schemaorg,unor/schemaorg,haonature/schemaorg,pwz3n0/schemaorg,vemmaverve/schemaorg,unor/schemaorg,callahanchris/schemaorg,haocafes/schemaorg,vholland/schemaorg,cesarmarinhorj/schemaorg,lanthaler/schemaorg,westurner/schemaorg,lanthaler/schemaorg,haonature888/schemaorg,tfrancart/schemaorg,tfrancart/schemaorg,haonature/schemaorg,dbs/schemaorg,vholland/schemaorg,Jonadabe/schemaorg,twamarc/schemaorg,gkellogg/schemaorg,ya7lelkom/schemaorg,haonature888/schemaorg,schemaorg/schemaorg,ynh/schemaorg,quantegy/schemaorg,dbs/schemaorg,lanthaler/schemaorg,hschema/schemaorg,quantegy/schemaorg,schemaorg/schemaorg,haocafes/schemaorg,sdo-sport/schemaorg,haonaturel/schemaorg,schemaorg/schemaorg,tfrancart/schemaorg,ynh/schemaorg,sdo-sport/schemaorg,vholland/schemaorg,URXtech/schemaorg,Jonadabe/schemaorg,URXtech/schemaorg,pwz3n0/schemaorg,schemaorg/schemaorg,cesarmarinhorj/schemaorg,gkellogg/schemaorg,twamarc/schemaorg,gkellogg/schemaorg,tfrancart/schemaorg,quantegy/schemaorg,sdo-sport/schemaorg,mfhepp/schemaorg,unor/schemaorg,mortizbank/schemaorg,hschema/schemaorg,cesarmarinhorj/schemaorg,gkellogg/schemaorg