Add get() method first example in joins section

Missing `get()` can be misleading to users.

queries.md

@@ -120,7 +120,8 @@ The query builder may also be used to write join statements. Take a look at the
  DB::table('users')
   ->join('contacts', 'users.id', '=', 'contacts.user_id')
   ->join('orders', 'users.id', '=', 'orders.user_id')
-  ->select('users.id', 'contacts.phone', 'orders.price');
+  ->select('users.id', 'contacts.phone', 'orders.price')
+  ->get();
 
 #### Left Join Statement