[DOCS] Adds docs for Scroll Helper

Author: picandocodigo

Diff for: docs/helpers.asciidoc

@@ -59,4 +59,41 @@ helper.ingest(documents) { |_, docs| puts "Ingested #{docs.count} documents" }
 
 === Scroll Helper
 
-=== Point in Time Helper
+This helper provides an easy way to get results from a Scroll.
+
+To use the ScrollHelper, you need to require it in your code:
+
+[source,ruby]
+----
+require 'elasticsearch/helpers/scroll_helper'
+----
+
+You need to instantiate a ScrollHelper with a client, an index, and a body (with the scroll API parameters) which will be used in every following scroll request:
+
+[source,ruby]
+----
+client = Elasticsearch::Client.new
+scroll_helper = Elasticsearch::Helpers::ScrollHelper.new(client, index, body)
+----
+
+There are two ways to get the results from a scroll using the helper.
+
+You can iterate over a scroll using the methods in `Enumerable` such as `each` and `map`:
+
+[source,ruby]
+----
+scroll_helper.each do |item|
+  puts item
+end
+----
+
+You can fetch results by page, with the `results` function:
+
+[source,ruby]
+----
+my_documents = []
+while !(documents = scroll_helper.results).empty?
+  my_documents << documents
+end
+scroll_helper.clear
+----

Diff for: elasticsearch/lib/elasticsearch/helpers/bulk_helper.rb

@@ -20,6 +20,7 @@ module Helpers
     # Elasticsearch Client Helper for the Bulk API
     #
     # @see https://www.elastic.co/guide/en/elasticsearch/reference/master/docs-bulk.html
+    #
     class BulkHelper
       attr_accessor :index
 

Diff for: elasticsearch/lib/elasticsearch/helpers/scroll_helper.rb

@@ -17,6 +17,10 @@
 
 module Elasticsearch
   module Helpers
+    # Elasticsearch Client Helper for the Scroll API
+    #
+    # @see https://www.elastic.co/guide/en/elasticsearch/reference/current/scroll-api.html
+    #
     class ScrollHelper
       include Enumerable