Fixing associations doc (#5834)

* Fixing associations doc

* Updating to nest where and attributes back under include

docs/docs/associations.md

@@ -265,7 +265,7 @@ User.findAll({
   include: [{
     model: Project,
     through: {
-        attributes: ['createdAt', 'startedAt', 'finishedAt']
+      attributes: ['createdAt', 'startedAt', 'finishedAt'],
       where: {completed: true}
     }
   }]