add sortByFictionalDate field to Story, and sorting by fictional date if set.

graph2/schema/types/Story.gql

@@ -33,6 +33,9 @@ type Story {
 
   # The date of the last major update to the story. This being bumped means a new chapter has been added.
   updatedDate: Time!
+
+  # Whether to sort by fictional date.
+  sortByFictionalDate: Boolean!
 }
 
 # Filter for stories query.
@@ -86,6 +89,9 @@ input StoryAddInput {
 
   # Set the fictional date of the story.
   fictionalDate: Time
+
+  # Whether to sort by fictional date.
+  sortByFictionalDate: Boolean
 }
 
 # Input for the editStory mutation
@@ -115,6 +121,9 @@ input StoryEditInput {
 
   # Clear the fictional date of the story.
   clearFictionalDate: Boolean
+
+  # Whether to sort by fictional date.
+  sortByFictionalDate: Boolean
 }
 
 # Input for the addStoryTag mutation