Fixing associations doc (#5834)

* Fixing associations doc

* Updating to nest where and attributes back under include

docs/docs/associations.md

@@ -264,10 +264,10 @@ With Belongs-To-Many you can query based on **through** relation and select spec
 User.findAll({
   include: [{
     model: Project,
-      through: {
-        attributes: ['createdAt', 'startedAt', 'finishedAt']
-          where: {completed: true}
-      }
+    through: {
+      attributes: ['createdAt', 'startedAt', 'finishedAt'],
+      where: {completed: true}
+    }
   }]
 });
 ```