Add support for images

lib/ezdoc/xml/relationships.rb

@@ -21,9 +21,11 @@ module Ezdoc
 
     class DocumentRelationships
       NAMESPACE = "http://schemas.openxmlformats.org/package/2006/relationships"
+      IMAGE_TYPE = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"
 
-      def initialize(has_numbering: false)
+      def initialize(has_numbering: false, images: [])
         @has_numbering = has_numbering
+        @images = images
       end
 
       def to_xml
@@ -36,6 +38,14 @@ module Ezdoc
                 Target: "numbering.xml"
               )
             end
+
+            @images.each do |image|
+              xml.Relationship(
+                Id: image.rid,
+                Type: IMAGE_TYPE,
+                Target: "media/#{image.filename}"
+              )
+            end
           end
         end
         builder.to_xml