make thumb optional

make-pages/Info.hs

@@ -27,7 +27,7 @@ data Info =
     nsfwTags    :: ![Text],
     description :: !(Maybe Text),
     images      :: ![Image],
-    thumb       :: !Text,
+    thumb       :: !(Maybe Text),
     links       :: ![Link]
   }
   deriving (Eq, Show)
@@ -71,7 +71,7 @@ instance FromYAML Info where
          <*> m .:? "nsfw-tags" .!= []
          <*> m .:? "description"
          <*> m .:  "images"
-         <*> m .:  "thumb"
+         <*> m .:? "thumb"
          <*> m .:? "links" .!= []
 
 instance FromYAML Artist where