Moves the setAuthor command to its own file

src/main/resources/plugin.yml

@@ -51,12 +51,16 @@ commands:
     permission: bookswithoutborders.setlore
   savepublic:
     description: Saves the held book to the public books folder
-    usage: /<command> [duplicate (true/false)]
+    usage: /<command> [overwrite (true/false)]
     permission: bookswithoutborders.savepublic
   save:
     description: Saves the held book to the holding player's folder
-    usage: /<command>
+    usage: /<command> [overwrite (true/false)]
     permission: bookswithoutborders.save
+  setauthor:
+    description: Sets the author of the held book
+    usage: /<command> <author>
+    permission: bookswithoutborders.setauthor
 permissions:
   bookswithoutborders.admin:
     description: Grants all permissions