Allow indexing a resource for the first time by manifest

refs #533

lib/tasks/index.rake

@@ -9,12 +9,12 @@ namespace :reindex do
     end
   end
 
-  desc 'Reindex a resource from a IIIF Manifest URL within an Exhibit'
+  desc 'Index or reindex a resource from a IIIF Manifest URL within an Exhibit'
   task :manifest, %i[manifest exhibit] => [:environment] do |_t, args|
     manifest = args[:manifest]
     exhibit_slug = args[:exhibit]
     exhibit = Spotlight::Exhibit.find_by(slug: exhibit_slug)
-    iiif_resource = IIIFResource.find_by(url: manifest, exhibit: exhibit)
+    iiif_resource = IIIFResource.find_or_initialize_by(url: manifest, exhibit: exhibit)
     iiif_resource.save_and_index_now
     puts "Reindexed the document for #{manifest}"
   end