Added add/edit/remove mutations for Chapter

schema/types/chapter.graphql

@@ -20,4 +20,40 @@ type Chapter {
 
   # The date of edit.
   editedDate: String!
+}
+
+# Input for addChapter mutation
+input ChapterAddInput {
+  # The story to add a chapter to
+  storyId: String!
+
+  # The title to give the chapter. It can not be left empty
+  title: String!
+
+  # The author to set for the chapter. It will use the logged in user ID, and only
+  # users with appropriate permissions can post as another author. Even then, it's only
+  # for importing/moving content. This author name will not be used when logging the 
+  # submission
+  author: String
+
+  # The markdown source for the content
+  source: String!
+
+  # Optionally, assign a fictional date for the chapter
+  fictionalDate: String
+}
+
+# Input for editChapter mutation
+input ChapterEditInput {
+  # The chapter to edit
+  id: String!
+
+  # Change the chapter's title
+  title: String
+
+  # Change the source
+  source: String
+
+  # Set the fictional date for a chapter
+  fictionalDate: String
 }